Luminous Landscape Forum
Site & Board Matters => About This Site => Topic started by: siba on March 05, 2010, 10:38:56 pm
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Mark Dubovoy has done an outstanding, pretty much unbiased test, which is pretty interesting.
And then he writes:
"The dynamic range of a typical high-end professional 35 mm DSLR is around 7 F/stops. Medium Format cameras are closer to 13 F/stops of dynamic range. You can see the difference from 30 feet away in a small print"
You can see the difference from 30 feet! well.....
I'm a phase one user. A professional photographer, who uses the phase one (P 45) for 99% of my work. I also use a canon 5D when light is bad and I'm shooting people, and I want to use the ambient light. I will bet everything I own, and everything my wife owns, that no person on this earth could tell the difference between a small print taken with a high end dslr and a high end medium format digital back from 30 feet (10metres) away.
Any takers?
Stefan Siba
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I will bet everything I own, and everything my wife owns, that no person on this earth could tell the difference between a small print taken with a high end dslr and a high end medium format digital back from 30 feet (10metres) away.
You sure about that bud? I used to do brackets of 1/6 of a stop on 8x10 film (and yes I COULD put the in the correct order on a 6' light box).
If you want to hold him to the term 30" "literally" then you might squeak out your bet hedge...but on the other hand, it's not hard to tell simply by subject matter and composition. at a first glance reaction, what was shot of a "serious" camera and a DSLR...
Obviously you aren't gonna be shooting a P 65+ in a seriously low light condition...so if I were a betting man, I would put my money on Mark being able to be more than 50% correct guessing on whether a given image was done on a real camera back vs a DSLR on a smallish print from 30" away...and I seriously wouldn't be betting MY wife on that deal! (ok that's not entirely what you said you would wager, but if you want to make it interesting).
:~)
Really, just from the point of shooting style and visual appearance, it ain't hard to tell what is shot handheld vs tripod...
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I found this article interesting partly because I've been testing my own ixpress 528c multishot back against my own phase p20. I've come to the opposite conclusion as Mark has - but I eliminated the camera and lens differences in his testing by using the same camera and lens - a Rollei 6008AF with schneider 150mm apo macro (and some testing with the 90 apo macro). I had a job to shoot paintings in a gallery for catalog and possible reproduction and carefully shot both backs using the same lighting, camera and lens. It appears that he the ixpress has better color fidelity, dynamic range, and actually a cleaner iso 400 shot too. The multishot and microstep functions of the 528c just leave the phase P20 for dead when it comes to color, tonality, detail, noise, etc. These are older backs, but the current software for processing. YMMV.
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Am I the only one who finds it curious about 13 stops of DR, and then we have the outside shot that's blown out on both?
The cyan shift is not uncommon when the blue channel blows.
Not sure where folks get their DR numbers from. I'm working with colour negative for some scenic stuff, and you really have to go some to get a blow-out, it's a rare event indeed. Now we can debate about the DR of neg film, but somebodies numbers are not adding up in the real world here.
Still interesting read, I liked the rant about pixel peeping, and even more so when I saw the 100% crop down the page ;-)
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.....I would put my money on Mark being able to be more than 50% correct guessing on whether a given image was done on a real camera back vs a DSLR.....
So you imply you think he is a lucky guy in guessing.....not that he really knows or can recognize, see the difference :-) :-)
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First - what definition of DR is being used? Second, you need to shoot proper backlit wide dynamic range charts to properly measure and test DR. If you just shoot a scene - even with as many parameters controlled as you can, how you can you measure it correctly when one camera will be more or less sensitive than the other. That will mean there might be highlight clipping on one camera, but much better shadow performance. Without a calibrated chart how can you see and measure that properly?
Graeme
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7 stops against 13...
For the sake of LL's credibility, wouldn't this better be amended?
Cheers,
Bernard
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Photos of newspapers and circuit boards are so helpful. Because I really dream of making the most excellent photos of newspapers and circuit boards.
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First - what definition of DR is being used? Second, you need to shoot proper backlit wide dynamic range charts to properly measure and test DR. If you just shoot a scene - even with as many parameters controlled as you can, how you can you measure it correctly when one camera will be more or less sensitive than the other. That will mean there might be highlight clipping on one camera, but much better shadow performance. Without a calibrated chart how can you see and measure that properly?
Graeme
If you have a full range shot, you can get a pretty good idea about the DR of a camera from a raw file as Emil Martinec (http://www.openphotographyforums.com/forums/showthread.php?t=4484) shows in this post on the Open Photography forum. Since digital sensors are linear, the exposure is proportional to the raw value. Unfortunately, this type of analysis is rare on this forum.
Regards,
Bill
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7 stops against 13...
For the sake of LL's credibility, wouldn't this better be amended?
Cheers,
Bernard
Yes, indeed. You could post a reference to the DXO site or post your own data, but it would be a waste of time since it would be ignored be the elitists on this forum who substitute "expert consensus" for data and scientific analysis.
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Slow down everyone.
Mark Dubovoy is one of the most respected people in the digital camera technology community. He also is a Phd nuclear physicist, which doesn't necessarily give him expertise in photography, but does speak to his understanding of the scientific method.
Mark regularly consults for some of the major companies in this industry, so of they listen to and respect his opinion don't be so quick to shoot him down, even though you may not agree with his assessment in this case.
I imagine that he'll respond here in due course, so lighten up on the name calling.
Michael
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...................Mark Dubovoy is one of the most respected people in the digital camera technology community. He also is a Phd nuclear physicist, which doesn't necessarily give him expertise in photography, but does speak to his understanding of the scientific method.
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Michael
What Mark Dubovoy set out to do in this article is a bit courageous because making these kind of comparisons is really and truly not easy. One needs to "normalize" for many variables, do lots of testing both on display and in print, then think hard about what the results say. Hence, I was impressed with this article. I think Mark went to great length with painstaking methodology and lots of time to address all the potential pitfalls - at least that I could think of - and more, so cudos; and well-written. This was done by a scientist with the relevant experience to know what to do and how to do it.
That said, there were only two points of detail which I picked-up on: (i) the DR question; according to DxO the latest crop of high-end DSLRs are in the 12 stop range, while the Phase P40/P65 are 13.7 stops, so it wasn't clear to me where 7 stops came from; (not to say that DxO is an icon of perfection - they claim Phase P40/65 backs are 15 bit, but they are 16 according to Phase-1, and they have different low light ISO ratings for the two sensors which are identical except for the number of pixels); (ii) I was wondering about the use of f/11 for the lenses - perhaps a tad smaller aperture than ideal in terms of diffraction - another complex issue - or are the guidelines different for MF than for 35mm DSLR (i.e. about 2 stops above maximum aperture for minimizing diffraction and maximizing resolution - admittedly *guidelines* - not rules of law for all lenses). I have no doubt Mark selected f/11 for a reason, so I'll be interested to hear why.
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If you want to hold him to the term 30" "literally" then you might squeak out your bet hedge...but on the other hand, it's not hard to tell simply by subject matter and composition. at a first glance reaction, what was shot of a "serious" camera and a DSLR...
Jeff, the article says 30 FEET, not inches. Unless someone has superhuman vision, telling any difference between like prints from different cameras at this distance would be amazing. I don't have any horse in this race other than this statement. I found the comparison quite interesting to read given these cameras are way beyond both my interest and price range. What I will do is my own experiment to compare a small print from my Canon S90 and Nikon D300 and see at what point I can tell the difference. Will report back to all but I don't hold much faith that I can do this at 30 feet.
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Just a general question for those who conduct such comparisons. If measurements rather than subjective evaluations are desired, why not use Imatest ? Norman Koren was featured in the LLVJ.
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Well, I certainly beleive Mark's comment about the differences that can be seen from a distance. 30 feets? 20 or 40 does it matter?
Just look in LU-LA Michael's photos. I've always found a noticiable difference when he uses MFD, and all the images are drasticaly downsampled for the web, despite, it is already visible at that size-resolution.
I found the article well done and much more precise than the Rockwell's Mamiya review for example.
It gives tendencies and, I think, brings some light about 2 star products.
In that sense Mark has succeded very well.
Regards,
Fred.
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I enjoyed the article, and I always find everything Mark Dubovoy writes interesting.
When I started this thread I certainly didn't want anyone criticizing the article per say.
It would be great if more people took the time and energy to give us such objective insights and comparisons.
It was purely the 30 feet away ability to tell the difference between a DSLR image and medium format back image which stood out as a surprising thing to claim. I took it as slightly toungue in cheek, and thus was willing to bet even my wife's possessions. 30 feet is a long way away to be able to tell anything much at all about a small print.
regards
Stefan
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Mark regularly consults for some of the major companies in this industry, so of they listen to and respect his opinion don't be so quick to shoot him down, even though you may not agree with his assessment in this case.
Hamamatsu, Nikon, etc... all agree on this definition
"The dynamic range value, however, corresponds to the limiting situation in which the full well capacity of a sensor element is reached, and is defined as follows:
Dynamic Range = Full Well Capacity (electrons) / Read Noise (electrons)"
A difference of 6 stops is.... hmmmm.... quite significant, and you don't have many factors to play with.
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Hi,
Measurement is one thing and perception another. Whom to believe? Perception is capricious. If measurements don't agree with perception we need to refine the measurement, or what we measure. I have this far not seen anything that could explain a five stop advantage with MFDB over DSLR in a scientifically feasible way.
It's a bit similar to audio. Simple measurements don't necessarily reflect perception. On the other hand, some people can hear difference in gold plated TOS cables and plain ones, which is obviously nonsense.
My last guess is that lenses play a major role. Better lenses with better coating, carefully built, with blackened edges on lenses and baffling to keep internal reflections down will be better than similar lenses built with less care.
Best regards
Erik
What Mark Dubovoy set out to do in this article is a bit courageous because making these kind of comparisons is really and truly not easy. One needs to "normalize" for many variables, do lots of testing both on display and in print, then think hard about what the results say. Hence, I was impressed with this article. I think Mark went to great length with painstaking methodology and lots of time to address all the potential pitfalls - at least that I could think of - and more, so cudos; and well-written. This was done by a scientist with the relevant experience to know what to do and how to do it.
That said, there were only two points of detail which I picked-up on: (i) the DR question; according to DxO the latest crop of high-end DSLRs are in the 12 stop range, while the Phase P40/P65 are 13.7 stops, so it wasn't clear to me where 7 stops came from; (not to say that DxO is an icon of perfection - they claim Phase P40/65 backs are 15 bit, but they are 16 according to Phase-1, and they have different low light ISO ratings for the two sensors which are identical except for the number of pixels); (ii) I was wondering about the use of f/11 for the lenses - perhaps a tad smaller aperture than ideal in terms of diffraction - another complex issue - or are the guidelines different for MF than for 35mm DSLR (i.e. about 2 stops above maximum aperture for minimizing diffraction and maximizing resolution - admittedly *guidelines* - not rules of law for all lenses). I have no doubt Mark selected f/11 for a reason, so I'll be interested to hear why.
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I can see that my remarks about Dynamic Range have sparked quite a bit of discussion. Thank you all. This is very healthy and quite interesting.
So let me explain where I am coming from:
About a year ago I was very curious about how the dynamic range of DSLR's compared to film. Part of my curiosity came because I had heard a few professional photographers complain that DSLR's could not approach film in this regard. I made a number of calls to Canon, Nikon, Kodak and Fuji. There was a universal consensus among the technical experts at these companies that top DSLRs delivered roughly 7 F/stops of dynamic range while most transparency film (there are obviously variations) delivered about 8 F/stops of dynamic range. The point was that they were relatively close. Negative film had somewhat higher dynamic range, according to Fuji about an extra F/stop.
It is important to note that during those discussions dynamic range meant how many F/stops you could capture and still deliver texture and detail.
No, I did not perform any tests. Since there was universal agreement, I took them at their word.
Now, turning to Medium Format, the factory spec for PhaseOne backs is approximately 13 F/stops. I know from experience shooting with these backs that they do deliver this kind of dynamic range.
This is how I came up with the numbers.
My experience with a Canon 1DsMKIII and my P65+ back certainly bears out a huge difference in dynamic range capabilities. I have never done a side-by-side measurement, but there is definitely a very large difference; 6 F/stops would not surprise me at all.
The reason for my comment of 30 feet is based on recent anecdotal evidence. About one week before I started writing the article, I went to the camera store and I had with me an 8x10 inch print from an image that I shot using an ALPA camera with the P65+ back. A couple of photography enthusiasts entered the store, and from about 30 feet away I heard one of them say "WOW, look at the dynamic range in that picture". Then, they approached me and kept asking how many shots it took, and how I did the HDR processing of the multiple shots, etc. They were stunned that this came from a single image capture. They also commented that "you could never get that kind of dynamic range out of a single image with a small format DSLR". There are two salient points here: First: One of the striking things about high end Medium Format backs is their dynamic range capabilities. Second: You can detect it from quite far away. If you do not like 30 feet, then make it 10, or whatever makes you feel good.
I would never state as fact something based on a single instance of anecdotal evidence, but this short piece of anecdotal evidence is typical and constantly repeats itself. I find that (if the original subject has it), the first thing that strikes the viewer about a Medium Format digital image is the dynamic range. The second thing is the level of detail retrieval and natural looking sharpness.
Having said all that, I am always interested in new evidence and new data, and if there is proof that some newer small DSLR (I have never used or tested a D3x for example) can match the Medium Format backs in dynamic range, I will be the first one to be ecstatic that the technology is getting better, and I will also stand corrected. If anyone has the right measurements and/or the proper visual experience, please be so kind as to share it.
To summarize: My visual experience to date, combined with what I have heard from the manufacturers themselves points to a very significant difference in Dynamic Range capabilities between Medium Format and smaller DSLR's.
I hope this is helpful, and again thanks to all of you for the discussion.
Mark Dubovoy
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No, I did not perform any tests. Since there was universal agreement, I took them at their word.
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A couple of photography enthusiasts entered the store, and from about 30 feet away I heard one of them say "WOW, look at the dynamic range in that picture".
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To summarize: My visual experience to date, combined with what I have heard from the manufacturers themselves points to a very significant difference in Dynamic Range capabilities between Medium Format and smaller DSLR's.
I'm speechless - good thing LL is free as otherwise I'd be demanding my money back.
My experience with a Canon 1DsMKIII and my P65+ back certainly bears out a huge difference in dynamic range capabilities. I have never done a side-by-side measurement, but there is definitely a very large difference; 6 F/stops would not surprise me at all.
DXOmark lists Canon 1Ds MkIII you have tested to have quarter of a stop less dynamic range as Phase P65 Plus. While there are certainly different ways to measure and interpret the results, going from 1/4 to 6 EV difference in DR with any interpretation would be shocking.
Several people have also shown empirically on these forums that MFDBs have little, if any, edge on DR. In fact, 1D MkIV has one stop more DR than both P65 and Hassy H3DII 50.
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Hamamatsu, Nikon, etc... all agree on this definition
"The dynamic range value, however, corresponds to the limiting situation in which the full well capacity of a sensor element is reached, and is defined as follows:
Dynamic Range = Full Well Capacity (electrons) / Read Noise (electrons)"
A difference of 6 stops is.... hmmmm.... quite significant, and you don't have many factors to play with.
...Not to mention that, since the photosites of the D3x and the P65+, have the same size, there are also very few theoretical reason why the P65+ should have any advantage of DR.
One could mention CCD vs CMOS, but if anything the CMOS sensor is said to be less noisy, which has a great impact on DR from its very definition. The rest belongs to technology, and my bet if on Sony/Nikon vs Kodak or Dalsa. There is overall a very good correlation between R&D investments and the quality of the resulting technology...
So all things considered, it would in fact be surprising if the P65+ had better DR than that of, say, the D3x.
Regarding perceptions, the widespread impression that backs have more DR is the consequence of the system calibration in favour of under-exposure away from the ideal exposure to the right. The histogram of most backs shows values that are under-exposed relative to the actual values, which gives the false impression that highlights can be recovered better. It should be obvious for anybody familiar with DR measurements that shadow noise is the deciding factor in both theoretical and real world DR.
Cheers,
Bernard
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No, I did not perform any tests. Since there was universal agreement, I took them at their word.
Mark,
Then, may I suggest that you remove asap these comments from an otherwise interesting piece to which they very clearly don't belong?
There are reasons why some people decide to shoot with a MFDB. In the end the only justification for the price of these backs is the fact that some photographers are willing to pay that much money. Some of these reasons are totally justified (look, lenses, system, resolution of a single capture), the reality of others is a lot less clear, starting with DR.
I don't see why you feel the need to damage your reputation to comment on this last point without theoretical analysis nor actual measured evidence.
As far as the comments from the people having seen your print, I would leave it to them to write their own piece on the topic. I really hope you realize that there is only a weak relationship between the look of a print and the DR of the device used to capture the initial image. Their comments only speak about you abilities as a printer.
Final comment from me on this.
Cheers,
Bernard
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Yes, indeed. You could post a reference to the DXO site or post your own data, but it would be a waste of time since it would be ignored be the elitists on this forum who substitute "expert consensus" for data and scientific analysis.
I don't know whether they are elitists or whether that is a problem in itself. Many of them are very good photographers, which is the most important thing. I would agree that they are elitists in the regard and consider this as a very good thing.
Now, some once justified urban myths live long. Many people still think that Canon camera have the best high ISO in the market, or that Ansel Adams images have the highest resolution of any landscape image ever shot,...
Another thing is that the MFDB is enough of a club that the influence of the vendors is strong. I don't expect Phaseone and Hassy to deliver objective information about their products relative to the competition but there is a natural trend to believe things that are repeated ad nauseum by overal good people you know.
Finally, backs have enough objective differentiators not to have to over sell DR... but the problem is that most photographers actually don't need the resolution,... and in the end the belief that DR is superior remains an important factor in the decision. Once purchased, the slight under-exposure of the backs calibration provides good apparent highlight recovery (close to negatives than to slides) and most photographers actually like that since it is safer for them, so this valiates their initial belief.
So all in all, the belief about the superiority of the back for DR is comfortable for both the vendors and the buyers. It is here to stay.
Cheers,
Bernard
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DXOmark lists Canon 1Ds MkIII you have tested to have quarter of a stop less dynamic range as Phase P65 Plus. While there are certainly different ways to measure and interpret the results, going from 1/4 to 6 EV difference in DR with any interpretation would be shocking.
I was going to make this point myself but in the end decided not to - simply because I actually don't have any direct experience with the P65+ (I do have extensive experience with the 1DSMK3). Therefore I leave it to others (such as Mark) who have used both cameras to confirm or deny accordingly.
Experience has shown me however that the 1DSMK3 has significantly better DR than film (and I used to shoot film) so I raise an eyebrow at the comment that film has better DR than a DSLR (because it doesn't in my experience).
As to the D3X - having compared files from my friend's D3X to my 1DSMK3 we both agree that the D3X has the edge in DR. That puts it somewhere well above film and somewhere between the 1DSMK3 and the P65+ in DR in my book (the reference to the P65+ being purely based on DXO (as noted above I have no experience with it).
All of this is pretty much academic arm chair pissing contest stuff really. What really counts is getting the shot with the tool you have at hand. And all of these tools will do a great job in the hands of a skilled operator so I personally see little point in getting to hot under the collar about an individuals opinion and expression of that opinion.
Overall I thought Marks article was informative, well written and interesting (even if I don't agree with everything he wrote) - thank you Mark.
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...Not to mention that, since the photosites of the D3x and the P65+, have the same size, there are also very few theoretical reason why the P65+ should have any advantage of DR.
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Cheers,
Bernard
Bernard, I also have a professional deformation that tends to put faith in numbers - more than is often deserved actually - and in this case, I can tell you frankly the numbers don't tell the whole story. Phase-1 actually designs their own sensors. They've been in this business for many years and they have some of the brightest, mostg experienced people on the planet doing it. Dalsa manufactures the P40+ and P65+ under their supervision. There is much more to sensor design - both physically and firmware - than the pixel pitch would reveal. We had a very interesting seminar on that at the PODAS Death Valley workshop from Klaus Molgaard, their chief technologist. That was back in November amongst a lot of other stuff so I forget the details by now, but one always carries away certain basic messages from such sessions and I remember being impressed at the time that one needs to know a lot more about this than we can srumise from published specs.
I don't know whether you own an MF system, but I bought one mainly on the strength of the performance in deep shadow areas and the stunning resolution with the barest minimum of sharpening. As you undoubtedly know it takes patience to use it properly, but it returns more than I can expect from my Canon 1Ds Mk3. I went into an exploration of the MF environment very agnostic about whether the difference in IQ would be worth investing in, and in the final analysis I decided if I wanted the ultimate in image quality that a camera system could deliver, this is it - even for 13*19 inch prints. I took special care to evaluate my decision in that context, because I seldom print larger than that.
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All of this is pretty much academic arm chair pissing contest stuff really. What really counts is getting the shot with the tool you have at hand. And all of these tools will do a great job in the hands of a skilled operator so I personally see little point in getting to hot under the collar about an individuals opinion and expression of that opinion.
And that's why I rarely comment on technical posts or articles as people usually argue about arcane minutiae with absolutely no impact on real-life IQ.
The resulting discussions too often end up looking like high-end audiophiles discussing the merits of soaking your SPDIF contacts in goat-urine for less warble. This is especially true with MFDBs with their "microcontrast" and "tonality" which nobody seems to be able to quantify, or even agree on their definition. These terms and other claims are often thrown around to prove MFDB superiority, accompanied with a jedi-handwave.
But this front-page article claims one can "see the difference [between dSLR and MFDB DR] from 30 feet away in a small print" based on anecdotal evidence, and slashes several stops of dynamic range from dSLRs based on statements from "experts." Oh, and calls AA filter a "blurring filter." It's one thing to write a non-technical article, and another to make brow-raising quantitative statements unsupported by any semblance of the scientific method.
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Another thing is that the MFDB is enough of a club that the influence of the vendors is strong. I don't expect Phaseone and Hassy to deliver objective information about their products relative to the competition but there is a natural trend to believe things that are repeated ad nauseum by overal good people you know.
Finally, backs have enough objective differentiators not to have to over sell DR... but the problem is that most photographers actually don't need the resolution,...
Cheers,
Bernard
Bernard, please, let us set aside polemics and deal with facts. I don't know what club you're talking about or should I be paranoid because I'm not a member; now, while the Phase-1 people are very decent folks to do business with, I'd be insulted if I believed you thought they can sell me a bill of goods which defies my own vision. And you know, sometimes, although I hate to hear myself say this, there can be truth in advertising. Why shouldn't they be expected to deliver objective information about their own products? They're selling into a niche of people who aren't easily deceived by propaganda. Your comment seems to be taking the vendors as fundamentally dishonest and their customers for idiots. I can't imagine you really believe this. Now, when you say that most photographers don't need the resolution - again quite a statement - I wouldn't hazard a guess about what most photogrpahers need because I don't wear their shoes or occupy their mindsets. But I hope I know my own head. Do I "need" all that resolution? Maybe yes, maybe no, it depends, and for when I think I do, it sure is "nice to have".
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...Not to mention that, since the photosites of the D3x and the P65+, have the same size, there are also very few theoretical reason why the P65+ should have any advantage of DR.
Maybe not quite that simple, since the actual light sensitive area on each of the photo sites is quite a bit different. I believe only 10% of the surface of each CMOS site is light sensitive, whereas around 30% of each site on a CCD is light sensitive.
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Maybe not quite that simple, since the actual light sensitive area on each of the photo sites is quite a bit different. I believe only 10% of the surface of each CMOS site is light sensitive, whereas around 30% of each site on a CCD is light sensitive.
aren't they putting microlens (even in gapless design) on top of the surface to direct the light to those "actual light sensitive areas", are they ?
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I went into an exploration of the MF environment very agnostic about whether the difference in IQ would be worth investing in, and in the final analysis I decided if I wanted the ultimate in image quality that a camera system could deliver, this is it - even for 13*19 inch prints. I took special care to evaluate my decision in that context, because I seldom print larger than that.
Mark, Mark, Mark,
You seldom print larger than 13"x19" yet you've invested in an MFDB system??? What are we to think?
Are you the ultimate pixel-peeper?
Here's what Mark Dubovoy wrote about pixel peepers, to quote:
Beware Pixel Peepers! A typical P65+ file in TIFF format is 386 Megabytes. Hasselblad H3D II files are slightly over 300 Megabytes each. It is totally impractical to present multiple images of this size on line. Furthermore, to even begin to evaluate the color in one of these images requires a perfectly profiled and calibrated professional graphics grade display (no, your mighty 30-inch Apple or NEC or other “standard” computer displays are not even remotely up to the task). The images vastly exceed the color gamut of most monitors. Also, remember that a computer monitor is inherently a low resolution device. Even the best HD monitor has a resolution that pales in comparison to an inkjet printer. Add to that the fact that the images presented in the article are either screen shots or JPEGs in a much reduced color space (sRGB) and the conclusion is that if you try to “pixel peep” you are wasting your time and you are likely to reach meaningless conclusions.
Now to contrast this statement, I would like to describe my own experiences as regards pixel-peeping.
As one gets older, one tends to become more long-sighted. That is, reading requires spectacles, but the full moon on a clear night might still appear detailed.
So it was with me. About 16 years ago, reading became a bit of a strain, and the optician prescribed spectacles with a +1x magnification.
16 years later, those same spectacles required for ease of reading are now perfect for long distances, such as trees on the horizon or the moon on a clear night.
I don't need the spectacles to get around, drive a car etc. If I wasn't into Photography and wasn't concerned about resolution, I just wouldn't bother. But I know through experimentation, if I want to appreciate the maximum detail of a distant scene, I need spectacles with a +1x magnification.
If I want to pixel-peep two images on my monitor at 100%, or 200% or even 400%, I need spectacles with a +2.5 to +3x magnification.
If I want to see the maximum detail in a high quality HD source on my 65" plasma TV, I need spectacles of +1.25x magnification, and I need to sit no further than 2.4 metres (or 7ft 10in) from the screen.
I mention this just to demonstrate that I have no reason to believe that my eyesight is deficient when using the appropriate specatcles.
If one examines Mark Dubovoy's statement about pixel peeping more carefully, he seems to be implying that the print from the MFDB file is so significantly better than any crop at any enlargement viewed on the monitor, that pixel peeping is not relevant, partly because an inkjet printer has higher resolution than a monitor, and also because some printers have a slightly wider color gamut than even a good monitor.
I don't find these reasons at all credible in light of my own experiences. If the print is better than the view on the monitor (in terms of resolution at the appropriate magnification on the monitor), or in terms of color gamut which the monitor cannot display, then such differences are of a pixel-peeping magnitude.
Furthermore, Mark Segal, any 'additional' qualities you see in your 13"x19" print from an MFDB file (as opposed to a 35mm file), viewed from the distance you would read a book, will disappear from even a slightly greater distance, like 600mm, never mind 2.4 metres.
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No, I did not perform any tests. Since there was universal agreement, I took them at their word.
Mark, Mark, Mark...
Surely you must realize by this time that NOTHING any English speaking representative of Nikon or Canon is in the least bit useful (nor factual). It's not that that wouldn't WANT to tell the truth...it's just that nobody from Canon nor Nikon USA would possibly know the truth.
You really, seriously need to step away from the "7 stop range" you are attributing to DSLR cameras and revise it upwards...
I haven't done the "technical tests" (as though that somehow means something to the aesthetics of an image) but I would guess that DSLRs are in the range of 9-10 stops at their natural ISO (not pushed to higher ISOs).
Depending on your definition of usable range, DSLRs might go over 10 stops...but I doubt anybody who has used a medium format back would doubt the range to be in the 12-14 stop range (depending on your definition of usable range vs noise).
Aside from the off the cuff comments at the end of the article, I'm glad you did it...interesting and useful!
Thanks...
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Hi,
Just a few remarks. To begin with, it is really the question of dynamic range. There is a technical definition and by that definition the leading DSLRs are in excess of 12 stops and so they are easily in the same range as MFDBs. I would also say that this has been thoroughly investigated by DxO mark. Having double the amount of pixels would add 0.5 stop if all other factors were kept constant. This is essentially quite consistent with the DxO-findings which peg the Phase One P65 plus at 11.5 stops on screen but 13 stops in print (normalized to 8 MPixels). The Nikon 3DX comes in at 14/13.
The second issue is the DR of film, I have mostly used Velvia and could see no detail 2 stops over nominal exposure and very little at 2 stops under nominal. I normally would expose Velvia at +1.5 stops for white snow, for instance. No way I'd consider Velvia to have a dynamic range close to a DSLR! The discussion Mark had with the DSLR vendors may have stemmed from the vendors talking about JPEG. JPEG has by definition a dynamic range of 8 stops, but those 8 stops are in gamma compensated space. I don't know what this means in practice.
The last point is that prints really don't have a DR in much excess of 7 stops. That's absolutely true and can never be a discussion about. Why? Because max density on paper seems to be around 2.3 and minimum density around 0.1. So max density - min density is about 2.2. A stop is 0.3 density units so paper has a DR of about 7.3 stops. With some papers and BW 7.6 stops may be achievable.
Whenever we utilize DR in excess of 8 stops in print it can only be achieved careful mapping of brightness values to paper densities in order of getting the perception of great dynamic range.
Aside from my observations regarding DR the article was interesting to read. In my view the comparison photos were well designed for the intended purpose, namely to investigate the difference between single shot and multi shot.
Another observation I may make is that using a white background with a small subject put large demands on the "anti flare" measures in the camera and lens.
Best regards
Erik Kaffehr
I can see that my remarks about Dynamic Range have sparked quite a bit of discussion. Thank you all. This is very healthy and quite interesting.
So let me explain where I am coming from:
About a year ago I was very curious about how the dynamic range of DSLR's compared to film. Part of my curiosity came because I had heard a few professional photographers complain that DSLR's could not approach film in this regard. I made a number of calls to Canon, Nikon, Kodak and Fuji. There was a universal consensus among the technical experts at these companies that top DSLRs delivered roughly 7 F/stops of dynamic range while most transparency film (there are obviously variations) delivered about 8 F/stops of dynamic range. The point was that they were relatively close. Negative film had somewhat higher dynamic range, according to Fuji about an extra F/stop.
It is important to note that during those discussions dynamic range meant how many F/stops you could capture and still deliver texture and detail.
No, I did not perform any tests. Since there was universal agreement, I took them at their word.
Now, turning to Medium Format, the factory spec for PhaseOne backs is approximately 13 F/stops. I know from experience shooting with these backs that they do deliver this kind of dynamic range.
This is how I came up with the numbers.
My experience with a Canon 1DsMKIII and my P65+ back certainly bears out a huge difference in dynamic range capabilities. I have never done a side-by-side measurement, but there is definitely a very large difference; 6 F/stops would not surprise me at all.
The reason for my comment of 30 feet is based on recent anecdotal evidence. About one week before I started writing the article, I went to the camera store and I had with me an 8x10 inch print from an image that I shot using an ALPA camera with the P65+ back. A couple of photography enthusiasts entered the store, and from about 30 feet away I heard one of them say "WOW, look at the dynamic range in that picture". Then, they approached me and kept asking how many shots it took, and how I did the HDR processing of the multiple shots, etc. They were stunned that this came from a single image capture. They also commented that "you could never get that kind of dynamic range out of a single image with a small format DSLR". There are two salient points here: First: One of the striking things about high end Medium Format backs is their dynamic range capabilities. Second: You can detect it from quite far away. If you do not like 30 feet, then make it 10, or whatever makes you feel good.
I would never state as fact something based on a single instance of anecdotal evidence, but this short piece of anecdotal evidence is typical and constantly repeats itself. I find that (if the original subject has it), the first thing that strikes the viewer about a Medium Format digital image is the dynamic range. The second thing is the level of detail retrieval and natural looking sharpness.
Having said all that, I am always interested in new evidence and new data, and if there is proof that some newer small DSLR (I have never used or tested a D3x for example) can match the Medium Format backs in dynamic range, I will be the first one to be ecstatic that the technology is getting better, and I will also stand corrected. If anyone has the right measurements and/or the proper visual experience, please be so kind as to share it.
To summarize: My visual experience to date, combined with what I have heard from the manufacturers themselves points to a very significant difference in Dynamic Range capabilities between Medium Format and smaller DSLR's.
I hope this is helpful, and again thanks to all of you for the discussion.
Mark Dubovoy
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Hi,
Mark talks about DR and not resolution. Anyone, except a blind man/woman, could see a difference between black and white at 30 feet.
That said, I don't understand some of Mark's statement regarding DR.
Best regards
Erik
Jeff, the article says 30 FEET, not inches. Unless someone has superhuman vision, telling any difference between like prints from different cameras at this distance would be amazing. I don't have any horse in this race other than this statement. I found the comparison quite interesting to read given these cameras are way beyond both my interest and price range. What I will do is my own experiment to compare a small print from my Canon S90 and Nikon D300 and see at what point I can tell the difference. Will report back to all but I don't hold much faith that I can do this at 30 feet.
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Interesting read,
the only things i cough up on are the DR misinformation and that a NEC wide-gamut SpectraView II screen is not good enough for judging, according to his opinion. Only EIZO does the job ?! Anyway, seems Hasselblad and Phase One need to rethink their plastic bodies...
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Bernard, I also have a professional deformation that tends to put faith in numbers - more than is often deserved actually - and in this case, I can tell you frankly the numbers don't tell the whole story. Phase-1 actually designs their own sensors. They've been in this business for many years and they have some of the brightest, mostg experienced people on the planet doing it. Dalsa manufactures the P40+ and P65+ under their supervision. There is much more to sensor design - both physically and firmware - than the pixel pitch would reveal. We had a very interesting seminar on that at the PODAS Death Valley workshop from Klaus Molgaard, their chief technologist. That was back in November amongst a lot of other stuff so I forget the details by now, but one always carries away certain basic messages from such sessions and I remember being impressed at the time that one needs to know a lot more about this than we can srumise from published specs.
Hum... Mark, have you have heard the equivalent speech done by Sony/Nikon engineers? I believe that they also describe themselves as being the best in the world at what they do. In the end these are just claims.
Figures do tell the whole story, especially when they are measured on an actual device just like DR can be. We are not talking about doggy predictions resulting from a potentially flawed theoretical model, we are talking about hard facts here.
Cheers,
Bernard
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Bernard, please, let us set aside polemics and deal with facts. I don't know what club you're talking about or should I be paranoid because I'm not a member; now, while the Phase-1 people are very decent folks to do business with, I'd be insulted if I believed you thought they can sell me a bill of goods which defies my own vision. And you know, sometimes, although I hate to hear myself say this, there can be truth in advertising. Why shouldn't they be expected to deliver objective information about their own products? They're selling into a niche of people who aren't easily deceived by propaganda. Your comment seems to be taking the vendors as fundamentally dishonest and their customers for idiots. I can't imagine you really believe this. Now, when you say that most photographers don't need the resolution - again quite a statement - I wouldn't hazard a guess about what most photogrpahers need because I don't wear their shoes or occupy their mindsets. But I hope I know my own head. Do I "need" all that resolution? Maybe yes, maybe no, it depends, and for when I think I do, it sure is "nice to have".
Well, the value of a direct customer-vendor relationship in B2B business is proven enough to be a fact.
As far as vendors being liars and buyers idiots, these are your own words, I never wrote that nor implied that. There is a long list of possible behaviors between the most honest (and let's be clear stupid) one that would consist in emphasizing the weaknesses of one own's product vs the competition on the one end, and openly lying about both on the other hand.
Unless you have done a thorough measurement of the DR of your back vs that of high end DSLRs it would appear that you have believed the numbers proposed by the vendor of your back at least in absolute terms if not in relative terms compared to your previous camera. If not you may want to either present your test results, or phrase your position as an impression.
Regarding impressions, I am not sure about the 1ds3, but I know that my D3x gives me totally clean shadows at base ISO, with a potential for lifting so high that I have hardly done any HDR in 1.5 years. I don't feel any need whatsoever to do any HDR in outdoor conditions, however harsh the light. The only case where I still do it is in some interior/exterior cases where even the human eye had problems dealing with the contrast in one shot.
So there you go, we have similar impressions with different devices, I suggest we use numbers to make things more objective.
Cheers,
Bernard
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There we go. It was a topic about comparing 2 MFD cameras and we are now in the war between 35mm FF cmos and MFD ccd lovers...
In that non-ending war, everybody becomes an engineer and scientist for a while. We will soon have graphics, mathematical equations and home made thesis. But very little real image comparaison.
And now the snobish factor in order to explain why there are still crazy photographers ready to spend a fortune in MFD while they all should better buy a D3x ?
Are we serious, really??
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Wayne,
I think you are right on the issue, although the percentages may be a bit higher according to my reading. CMOS sensors normally have microlenses, which compensate for part of the difference between CMOS and CCD. Sony works on a back illuminated sensor where the wiring and logic is behind the actual sensor cells. I got the impression that this arrangement gives about one step in sensitivity.
On the other hand, DR is depending on well capacity and readout noise. Well capacity seems to be in the same neighborhood in P65 and and 20-25 MP CMOS according from what I have seen. MFDBs used to have higher readout noise than DSLRs but this may not be the case with the present generation of digital backs.
It's a bit odd to me that native ISO for CMOS tends to be around 200, while MFDB-s are significantly lower. Having about the same well capacity and "quantum efficiency" I would expect that native ISO would be about the same. Interestingly, the Leica S2 has a native ISO of 160 with an option to "pull" to reduce ISO.
One area which has not been discussed but may explain some differences is the efficiency of the color filter grid. If the RGB filters are narrow and have steep gradients saturated colors may be easier to achieve. This would also reduce ISO. On the other hand, in our own vision there is a significant overlap between spectra sensitivity of the receptors, so it may be easier to reproduce the metameric behavior of the human vision with more overlapping sensels.
[attachment=20727:ColorResponse.jpg]
Best regards
Erik
Maybe not quite that simple, since the actual light sensitive area on each of the photo sites is quite a bit different. I believe only 10% of the surface of each CMOS site is light sensitive, whereas around 30% of each site on a CCD is light sensitive.
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My last post was a premonition saying "we will soon have graphics"....
And you just did it Erik.
Why can't we have once for awhile real pictures comparaisons in real work situations, made in such scientifical way that it will be unquestionable?
Instead of graphics and theories.
That would just put an ultimate light on the endless topic.
Anybody with a D3s and Phase or Hasselblad for doing this ?????
Regards,
Fred.
Wayne,
I think you are right on the issue, although the percentages may be a bit higher according to my reading. CMOS sensors normally have microlenses, which compensate for part of the difference between CMOS and CCD. Sony works on a back illuminated sensor where the wiring and logic is behind the actual sensor cells. I got the impression that this arrangement gives about one step in sensitivity.
On the other hand, DR is depending on well capacity and readout noise. Well capacity seems to be in the same neighborhood in P65 and and 20-25 MP CMOS according from what I have seen. MFDBs used to have higher readout noise than DSLRs but this may not be the case with the present generation of digital backs.
It's a bit odd to me that native ISO for CMOS tends to be around 200, while MFDB-s are significantly lower. Having about the same well capacity and "quantum efficiency" I would expect that native ISO would be about the same. Interestingly, the Leica S2 has a native ISO of 160 with an option to "pull" to reduce ISO.
One area which has not been discussed but may explain some differences is the efficiency of the color filter grid. If the RGB filters are narrow and have steep gradients saturated colors may be easier to achieve. This would also reduce ISO. On the other hand, in our own vision there is a significant overlap between spectra sensitivity of the receptors, so it may be easier to reproduce the metameric behavior of the human vision with more overlapping sensels.
[attachment=20727:ColorResponse.jpg]
Best regards
Erik
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Experience has shown me however that the 1DSMK3 has significantly better DR than film (and I used to shoot film) so I raise an eyebrow at the comment that film has better DR than a DSLR (because it doesn't in my experience).
It's not just about the DR number, it's "where the DR is" Regarding negative film, it's got a pretty impressive roll off in the highlights, digital is the reverse..it's mostly all in the shadows. Pulling up hard shadows wise, watching the highlights to avoid clipping..I can get not too far from neg film..but it's not really the same, hues and colours shifting can be an issue. Obviously raw and low ISO are a must.
Films vary in DR too, so a blanket statement cannot hold any water. I've serious doubts any DSLR at any price can match some of the b&w films either, FP4 has a simply massive latitude, over and underexposure wise. The only company to seriously attempt good DR via a sensor is Fuji, shame we don't see more of this.
But more to the point..in many cases having a big highlight latitude is more useful. If we added 2-3 stops more highlight end on most DSLR's, you'd hear next to no complaints about burnt out highlights.
I'm glad were talking about DR though, it's an important point, and often takes a back seat to "resolution"
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It's not just about the DR number, it's "where the DR is" Regarding negative film, it's got a pretty impressive roll off in the highlights, digital is the reverse..it's mostly all in the shadows. Pulling up hard shadows wise, watching the highlights to avoid clipping..I can get not too far from neg film..but it's not really the same, hues and colours shifting can be an issue. Obviously raw and low ISO are a must.
Films vary in DR too, so a blanket statement cannot hold any water. I've serious doubts any DSLR at any price can match some of the b&w films either, FP4 has a simply massive latitude, over and underexposure wise. The only company to seriously attempt good DR via a sensor is Fuji, shame we don't see more of this.
But more to the point..in many cases having a big highlight latitude is more useful. If we added 2-3 stops more highlight end on most DSLR's, you'd hear next to no complaints about burnt out highlights.
I'm glad were talking about DR though, it's an important point, and often takes a back seat to "resolution"
I completely agree with this point Barry. One of my best friend worked a lot with the Fuji and indeed this was one step ahead in DR. May I risk to say also the Foveon solution? But in both case, resolution was in question, so is there a relation between DR and resolution output?
Then it would easily explains in part why the MFD have an advantage over 35mm. But I'm not a scientist neither an expert.
Fred.
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can anyone out there add to this and/or shed some light on the following. i have the p65 but when used with a Horseman SWD2Pro and a 24xl Schneider Lens i find there is vignetting and purple fringing due the image circle of the lens being too small when using the full frame P65. i have come to understand through correspondance from Eric Joakimand at Phase One and the guys from Alpa and Teamwork Digital that when using a technical camera, the only wide angle lens that has an image circle large enough is the Rodenstock 23mm HR Digaron. But, you cant use it with shift/tilt. does anyone know when either Schneider or Rodenstock are going to bring out wide angle lenses with large enough image circles to be used effectively with the full frame P65. Thomas at Alpa suggests the following to be released mid 2010 - (Schneider: a new 28mm lens with a large image circle of probably 90mm diameter; Rodenstock: a new 32mm lens also with a large image circle). the HTS 1.5 apparently when used with the 28mm lens causes a crop factor to be introduced and thats only using the 50mp back. what will be the case with the new 60mp Hassleblad sensor. will the tilt/shift be limited and will their still be a crop factora and by how much? also. with Mark's comparison of the two cameras, can they compare to technical cameras in terms of quality. thanks.
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I completely agree with this point Barry. One of my best friend worked a lot with the Fuji and indeed this was one step ahead in DR. May I risk to say also the Foveon solution? But in both case, resolution was in question, so is there a relation between DR and resolution output?
Then it would easily explains in part why the MFD have an advantage over 35mm. But I'm not a scientist neither an expert.
Fred.
Gentlemen,
All the sensors used in all photographic devices on the market today can be considered to be perfectly linear devices up to the point where they saturate, including the Fuji S5 Pro.
There are only 2 key differences between sensors:
- how the system is calibrated in terms of exposure and in camera histogram (this can give the impression of the ability to recover highlights),
- how clean the shadows are.
In the future we will be getting non linear sensor able to handle infinitely bright illuminations with finite and differentiate RGB values, but we are not there today.
Cheers,
Bernard
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There we go. It was a topic about comparing 2 MFD cameras and we are now in the war between 35mm FF cmos and MFD ccd lovers...
Nope, the original article was mostly about comparing 2 backs and a little bit about comparing backs to DSLRs.
This thread is somce the beginning mostly about latter part.
Note that this thread would not have existed had the original article been realistic about the later point.
Cheers,
Bernard
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Cheers Bernard. Exactly. I started the thread purely because of that one sentence I quoted in the initial post.
The rest of the article was a really great comparison of two digital backs, that most of us wouldn't be able to easily get our hands on and do ourselves.
Fred, as I stated I'm a Phase user, and wouldn't normally care about comparisons between DSLR and MFDB. There was a time, three years ago or so, when I thought there was no comparison. But, nowadays, even though I shoot mostly MFDB, I have no qualms about doing a shoot with my DSLR if the situation calls for it. I have come to see in my professional, real world, handing files over to clients, that there is not that huge a difference.
Therefore, at 1 in the morning, when I was happily reading the article - happy to have a new article by Mark Dubovoy, and a glass of wine, the sentence about being able to see the difference in DR of a DSLR small print versus a MFDB small print from 30 feet away jumped out of the page, and it seemed like bar talk. If a photographer mate of mine would have made the same sweeping comment I would have immediately reacted. So, I couldn't help myself and started the thread.
And Erik, you have made the same sort of sweeping comment that has made me come in once again. According to you a "blind man" can tell the difference between two small prints at thirty feet. That the issue is just being able to discern between black and white in the two prints.
I quote Mark again:
"The dynamic range of a typical high-end professional 35 mm DSLR is around 7 F/stops. Medium Format cameras are closer to 13 F/stops of dynamic range. You can see the difference from 30 feet away in a small print"
This sentence implies that the dynamic range of DSLRs and MFDBs is so astronomically different that it is immediately apparent from thirty feet away. Erik, you are agreeing with this. I just can't agree. If you take a photo of the same scene under the same conditions and take the same care with printing, then from thirty feet away I don't believe anyone could tell the difference, from two 8x10 prints, which was DSLR and which was MFDB. Not with any certainty at all. If I was just talking to mates in a bar I would be more adamant about this, but because we are in a forum, I am just politely suggesting that this one sentence is cause for discussion. Even though we've obviously been there before.
Now if it was just a question of semantics then I don't think I would have bothered reacting. But this is fighting talk . And I'm usually on the side of the Digital backs. Not so in this case
cheers all,
Stefan
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Nope, the original article was mostly about comparing 2 backs and a little bit about comparing backs to DSLRs.
This thread is somce the beginning mostly about latter part.
Note that this thread would not have existed had the original article been realistic about the later point.
Cheers,
Bernard
I agree Bernard.
I read your posts carrefuly, and you certainly point some interesting details. But in another topic (about the pentax MFD), you assumed that the 645D could be a game changer. Maybe I did not understood in what way or context you pointed that fact, and how could it be a game changer in the current panorama.
I simply think that in these kind of debates, there is fast much more writings and concepts that images, in a website dedicated to...image. So what happen is that we have an incredible amount of arguments but very little real life images in order to endorse the arguments. Yes, a lot of graphics.
At the end, we all looking and participating for better information, and the overall sensation that I get is that there is more confusion.
Best regards,
Fred.
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There are numerous backlit dynamic range charts - all we need to do is point a range of cameras at them and publish the images. This discussion on 35mm v MF DR comes up time and again, and nice though DxO numbers are, I think we all need to see the test images.
Another point - "highlight DR" is just about where you set your mid grey. The less noisy the sensor, the lower you can set the mid grey and the more highlight protection you can build into the development gamma curve. That is why it's important to take the DR test measurement back to linear light to compare cameras properly. Once you know how many stops your camera protects in the highlights - where it biasses mid grey effectively, you can use exposure compensation to adjust accordingly, or even on a scene by scene basis. In the end, it's just another way of looking at ETTR.
Graeme
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Please see my Editor's Note (http://www.luminous-landscape.com/reviews/cameras/h3d50ii.shtml#update) just added to Mark's review. It will hopefully shed some light on the DR question.
Michael
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Please see my Editor's Note (http://www.luminous-landscape.com/reviews/cameras/h3d50ii.shtml#update) just added to Mark's review. It will hopefully shed some light on the DR question.
Michael
I think your "standard definition" of DR, "The standard definition of dynamic range in the industry has always been how many F stops above and below middle gray can be recorded while delivering full texture and detail", is from the film era. Digital is linear and does not have any inflection point in the mid range. Middle gray has no special significance in a linear digital characteristic curve and we don't meter for middle gray but rather for the highlights. In any case, we are more interested in the total DR. The standard definition of DR for digital sensors is the full well capacity divided by the read noise. This engineering definition sets the noise floor quite low and photographers might set the floor at a higher value. For objectivity, a signal:noise cutoff should be used in this case.
This is the approach taken by Norman Koren (who was recently featured in a LuLu video review) in Imatest. For example, with my Nikon D3 at base ISO and a Stouffer wedge, I get the shown results when rendering into a 16 bit TIFF with ACR set at defaults but with a black point of 0 (using the default black clips the shadows and gives a DR of 7 stops).
[attachment=20738:Stouffer...0_Step_2.png]
According to Roger Clark's data, the D3 has a full well of 65500 electrons and a read noise of 17.6 electrons at base ISO, giving a calculated DR of 11.8 stops. DXO gives the D3 a screen DR (per pixel) of 11.92 stops. That compares with the low quality DR of 11.9 stops in my tests. For high quality results, the DR is only 7.82 stops.
To get a better idea of how MFDBs compare to DSLRs, why doesn't someone with a P65+ post some data?
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There are numerous backlit dynamic range charts - all we need to do is point a range of cameras at them and publish the images. This discussion on 35mm v MF DR comes up time and again, and nice though DxO numbers are, I think we all need to see the test images.
Another point - "highlight DR" is just about where you set your mid grey. The less noisy the sensor, the lower you can set the mid grey and the more highlight protection you can build into the development gamma curve. That is why it's important to take the DR test measurement back to linear light to compare cameras properly. Once you know how many stops your camera protects in the highlights - where it biasses mid grey effectively, you can use exposure compensation to adjust accordingly, or even on a scene by scene basis. In the end, it's just another way of looking at ETTR.
Graeme
+1. See my previous post.
Bill
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Please see my Editor's Note (http://www.luminous-landscape.com/reviews/cameras/h3d50ii.shtml#update) just added to Mark's review. It will hopefully shed some light on the DR question.
Michael
With all due respect, you don't need to believe in DxO or have access to a MFD back to have an view on the dynamic range - by your definition - of your own DSLR.
Right?
If we all agree that good slide film could deliver 8 stops, then I think I get at least 10 from my D700.
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Hi,
Thanks for the note!
Just a few comments. I may feel it unjust to blame DxO for using the SNR equals one definition of DR, AFAIK it is the standard (textbook) definition. I do agree that SNR (Signal to Noise Ratio) of one is pretty useless, but that is another question. The way I see it DxO makes measurements of the sensors they need to make their DxO raw converter. They publish their results, which I see as a great service. The one thing I don't like with DxO is putting a single figure of merit on their measurements.
Another point is that much of the characteristics of a sensor is decided by physics. DR is definitively only affected by the number of free electrons generated by photons and the read noise. What Michael essentially says that the normal definition of DR is not relevant to photography and I can agree with that. On the other hand what is probably important to photography is what is known as shot noise a purely statistical variation of the number of photons reaching each sensel. Increasing the sensor size reduces noise, doubling the area of the sensor reduces noise with a factor of 1.41 (square root of two) to my understanding.
From a standpoint of physics I cannot see how a 4-5 stop advantage of MFDBs over DSLRs would be feasible. Would MFDBs really have much less noise than DSLRs they would also be able to use much higher ISO as they would be able to take like 4-5 steps of underexposure.
I have great respect for the knowledge and experience of both Marks and Michael, but I would really like to see some analysis which explains the differences in a way that makes sense to engineers.
The most comprehensive analysis I have seen is here:
http://www.clarkvision.com/articles/digita...mary/index.html (http://www.clarkvision.com/articles/digital.sensor.performance.summary/index.html)
Unfortunately, Dr. Clark does not discuss MFDBs, as far as I know,
Best regards
Erik
Please see my Editor's Note (http://www.luminous-landscape.com/reviews/cameras/h3d50ii.shtml#update) just added to Mark's review. It will hopefully shed some light on the DR question.
Michael
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The "quality" aspect seems to be important. Looking at the DR results on imaging resource, they use imatest, but have quality from low to high, jpeg and ACR best. Obviously there will be a point you can pull any image apart, esp shadow end..but if you get unprintable results, it's of no real value in the field in such cases, purely technical.
I guess someone is going to have to do this "Clint Eastwood" style, take a phase one, Hassie, and a respected DSLR out, take some real world shots, and if there really is a 5 stop gap DR wise, that would show up very quickly indeed. I'd be surprised if the MF digital's can get 13 stops of high quality DR, but I'd be curious to see that. I would not expect the MF ones to blow out like that if they did have huge DR, but I won't bar stool this one, I've never even seen either MF digital, let alone touched one ;-) I bet 13 stops has more to do with a technical test, rather than a high quality printable image. Ditto on DxO and Clarkvision, in particular some compacts seem to have a DR score that is not really believable for actual usable images.
Still, the discussion is useful, and interesting..and so far on this thread at least..seems civilised and respectful.
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Please see my Editor's Note (http://www.luminous-landscape.com/reviews/cameras/h3d50ii.shtml#update) just added to Mark's review. It will hopefully shed some light on the DR question.
Michael,
I was not aware that you had other problems with the relevance of DxO results besides them not factoring in resolution enough.
If follow up questions are allowed, how is the DxO definition of DR not taking the linearity of sensors into account? My view is that their definition only makes sense for the very reason that sensors are linear. If they were not, highlight behavior would be less clear, and there would be no way to base DR computation from a fixed reference in the highlights.
In fact, both definitions are very similar.
- On your side you use a film days concept called mid-grey and add the amount of stops on both sides to compute DR... DxO doesn't split the range.
- Other than that their definition and yours would be identical if "delivering full texture and detail" (the industry generally uses "perceivable detail" rather than "full detail") were equal to "signal to noise ratio equal to 0DB". This is indeed not the same, Full detail would correspond to a signal to noise ratio significantly higher than 0DB, and the resulting dynamic range would be lower than the value provided by DxO... but it would be lower for both the DSLR and the MFDB wouldn't it?
The question then becomes, why would DSLRs be impacted more by a more severe definition of noise floor compared to MFDBs?
Cheers,
Bernard
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Please see my Editor's Note (http://www.luminous-landscape.com/reviews/cameras/h3d50ii.shtml#update) just added to Mark's review. It will hopefully shed some light on the DR question.
Michael
Thank you for this Editor's Note.
Michael pointed exactly some concepts that I tried clumsily to express with my limited english.
It is also nice to see that the debate here in Lu-La is animated and sometimes hot but did not fall into uncontroled manners.
As a non-expert and in a learning process, I'm always interested to read everyone's point of view. But after a while, what I find is that there is a lot of presumed knowledge that seems to be given without real experience with these tools. Michael pointed this in the note and I think it is sadly often the case.
So, do we get a trustable or better information? I think we are all looking for that, no? But it turns into a passionate and conceptual answers game, like in a football stadium where each one supports his team, even if it means deny clearness.
For a not so technicaly knowledgable members like me, it is very frustrating and confusing because I do not know at the end who and what I can trust, and the only answer I got so far is I won't know it till I buy a MFD, work some time with it and see by myself.
I certainly can trust Michael because I know that he uses any kind of gear, from 4/3 to MFD and LF and I have no suspicions that he could be integrist of a system or another so his post was information to me. But in general I do not see very much, arguments that are served with images that illustrate them, so I tend to be carreful and keep an helphy distance. The question is, when you expose these physical and technical posts about DR etc...do you actually own a MFD ? or is it just DxO reading on the web? This point is important I think.
I also agree Siba, FF has changed and evolved, but till wich point?
When I pointed my desire of seeing more images and less theories, is just because there is a moment where images should also speaks.
Why not having for example a fashion session (controled light), like the one they did for the Leica S2, with 2 photographers experts in their gears?
1 with a Nikon D3s and one with a Phase or Hasselblad or Sinar m. Then putting the original files downlable, and see the results.
I think it would be really helpfull.
Cheers,
Fred.
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"For high quality results, the DR is only 7.82 stops."
Based on my experience with linear detectors in my day job (univ.prof. mass spectrometry) looking roughly at your data I would say you nailed it.
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Please see my Editor's Note (http://www.luminous-landscape.com/reviews/cameras/h3d50ii.shtml#update) just added to Mark's review. It will hopefully shed some light on the DR question.
I don't think this sheds any light on anything at all. If you want to argue that the absolute numbers produced by DxO's DR test are optimistic, and that a more real-world definition of photographically useful DR would result in smaller absolute numbers, that's fine.
But the real value of the DxO tests is that DxO is consistent in their testing methodology. So as long as you understand what the various tests are measuring, comparing the test results from two cameras will indeed give a meaningful indication of their relative performance. If we look at DxO's testing, there is nowhere near a 6-stop difference in performance between today's best DSLR's and MFDB's. And I'm sorry, but you cannot dismiss the DxO test as invalid with a flippant comment that "it does not take into account the linear nature of sensors." This statement is, to put it bluntly, absurd.
I will agree that today's latest MFDB's have some DR advantage over most DSLR's. But to claim that it is a 6-stop advantage cannot be taken seriously. If you have tests showing this, I think a lot of people would be very interested in seeing them. You seem to place high value on personal experience and real-world testing. Yet by his own admission, Mark used neither in coming up with his claims; rather, they are based on subjective impressions and anecdotes from disparate sources. IMHO you need better arguments that that if you're going to claim that
- Slide film has 1 stop more DR than DSLR's
- MFDB's have 6 stops more DR than DSLR's.
- The difference in DR between MFDB's and DSLR's can be distinguished in a small print from 30 feet away.
None of these can be taken seriously. And while Mark's anecdote relating to the last point is amusing, it's hardly relevant. For one thing, there was no comparison; they only saw an MF print from a distance. Furthermore, as another poster pointed out, the DR of DSLR's and MFDB's both exceed the DR of a physical print.
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I don't think this sheds any light on anything at all. If you want to argue that the absolute numbers produced by DxO's DR test are optimistic, and that a more real-world definition of photographically useful DR would result in smaller absolute numbers, that's fine.
But the real value of the DxO tests is that DxO is consistent in their testing methodology. So as long as you understand what the various tests are measuring, comparing the test results from two cameras will indeed give a meaningful indication of their relative performance. If we look at DxO's testing, there is nowhere near a 6-stop difference in performance between today's best DSLR's and MFDB's. And I'm sorry, but you cannot dismiss the DxO test as invalid with a flippant comment that "it does not take into account the linear nature of sensors." This statement is, to put it bluntly, absurd.
I will agree that today's latest MFDB's have some DR advantage over most DSLR's. But to claim that it is a 6-stop advantage cannot be taken seriously. If you have tests showing this, I think a lot of people would be very interested in seeing them. You seem to place high value on personal experience and real-world testing. Yet by his own admission, Mark used neither in coming up with his claims; rather, they are based on subjective impressions and anecdotes from disparate sources. IMHO you need better arguments that that if you're going to claim that
- Slide film has 1 stop more DR than DSLR's
- MFDB's have 6 stops more DR than DSLR's.
- The difference in DR between MFDB's and DSLR's can be distinguished in a small print from 30 feet away.
None of these can be taken seriously. And while Mark's anecdote relating to the last point is amusing, it's hardly relevant. For one thing, there was no comparison; they only saw an MF print from a distance. Furthermore, as another poster pointed out, the DR of DSLR's and MFDB's both exceed the DR of a physical print.
Jeff,
I really like your landscape photographs and I think you are a knowledgable photographer. That is why your post surprises me. How do you give that much credit to DxO and not the same credit to photographers who works daily with MFD ?
But then I also see that you work with D3x, so is it that you are really serious in your post or in a way you defend your gear?
Because then, how can you explains the enormous amount of top photographers that are working in fashion, landscape, arquitecture and fine arts who only work with MFD or LF ?
I'd like to see a real world comparaison between the Nikon and some MFD, with texture clothes, complex patterns, difficult light etc...to see if this DxO is trustable in the real world. Numbers are one thing, and DxO is NOT absolute mathematics calculations but just a way of testing, reality is another story.
In my understanding of course and with all my respect.
Cheers.
Fred.
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How do you give that much credit to DxO and not the same credit to photographers who works daily with MFD ?
I don't think DxO tests are the only meaningful measurement of camera performance. Having said that, I also do not think you can dismiss the DxO tests out of hand, just because you don't like the results or the results disagree with previously-held beliefs.
But then I also see that you work with D3x, so is it that you are really serious in your post or in a way you defend your gear?
I'm under no delusions that my D3x is better than the P65. There are certainly aspects of image quality where such a back far exceeds any DSLR, with resolution being an obvious one, but also color depth. I don't think DSLR's are just as good as MFDB's, and never said that. If the P65 cost under 10 grand and had in-back live-view, I would be shooting one.
The three specific statements I took exception with were:
- Slide film has 1 stop more DR than DSLR's
- MFDB's have 6 stops more DR than DSLR's.
- The difference in DR between MFDB's and DSLR's can be distinguished in a small print from 30 feet away.
I may not think my D3x is as good as a P65, but I still disagree with those statements, especially with no factual basis or even personal experience from the author of those statements to back them up.
Because then, how can you explains the enormous amount of top photographers that are working in fashion, landscape, arquitecture and fine arts who only work with MFD or LF ?
There are plenty of reasons to choose MFDB: leaf shutter for fast sync with strobes, ability to use a view camera with the full range of movements, high resolution for retouching or large prints (DSLR stitching is sometimes a good approach for the latter, but not always), etc. Again, I never said there's no reason to use MF; a 6-stop DR advantage just isn't one of them.
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Thanks for these precisions Jeff.
Cheers,
Fred.
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Hi,
My view is that DxO does unbiased and scientifically sound work. I certainly feel they deserve a lot of respect for publishing their results, no one else is doing a similar effort. So I'm much against DxO bashing.
The way I see it sometimes the DxO numbers agree with our expectations and than we say that they are great, sometimes they don't fit our expectations than we say they are not so great.
What folks need to realize that photography is about perception and perception is not really the same as physics. There is always a possibility that measurements don't measure the right parameters the right way, or that they are not easy to interpret. There is always a temptation to condense all findings into a single "figure of merit", in my view it's simply a stupid approach.
My view on this discussion may be:
- Some of Mark Dubovoy's observations regarding DR need some elaboration or evidence. They certainly seem to contradict basic science. I may be wrong on this but would really like to see some explanation, proof or evidence.
- It's not possible to reproduce a DR in excess of 7 to eight step in a print without manipulating tonality. So if we discuss prints, we also discuss processing.
Best regards
Erik
Jeff,
I really like your landscape photographs and I think you are a knowledgable photographer. That is why your post surprises me. How do you give that much credit to DxO and not the same credit to photographers who works daily with MFD ?
But then I also see that you work with D3x, so is it that you are really serious in your post or in a way you defend your gear?
Because then, how can you explains the enormous amount of top photographers that are working in fashion, landscape, arquitecture and fine arts who only work with MFD or LF ?
I'd like to see a real world comparaison between the Nikon and some MFD, with texture clothes, complex patterns, difficult light etc...to see if this DxO is trustable in the real world. Numbers are one thing, and DxO is NOT absolute mathematics calculations but just a way of testing, reality is another story.
In my understanding of course and with all my respect.
Cheers.
Fred.
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Mark, Mark, Mark,
You seldom print larger than 13"x19" yet you've invested in an MFDB system??? What are we to think?
Are you the ultimate pixel-peeper?
Here's what Mark Dubovoy wrote about pixel peepers, to quote:
Now to contrast this statement, I would like to describe my own experiences as regards pixel-peeping.
As one gets older, one tends to become more long-sighted. That is, reading requires spectacles, but the full moon on a clear night might still appear detailed.
So it was with me. About 16 years ago, reading became a bit of a strain, and the optician prescribed spectacles with a +1x magnification.
16 years later, those same spectacles required for ease of reading are now perfect for long distances, such as trees on the horizon or the moon on a clear night.
I don't need the spectacles to get around, drive a car etc. If I wasn't into Photography and wasn't concerned about resolution, I just wouldn't bother. But I know through experimentation, if I want to appreciate the maximum detail of a distant scene, I need spectacles with a +1x magnification.
If I want to pixel-peep two images on my monitor at 100%, or 200% or even 400%, I need spectacles with a +2.5 to +3x magnification.
If I want to see the maximum detail in a high quality HD source on my 65" plasma TV, I need spectacles of +1.25x magnification, and I need to sit no further than 2.4 metres (or 7ft 10in) from the screen.
I mention this just to demonstrate that I have no reason to believe that my eyesight is deficient when using the appropriate specatcles.
If one examines Mark Dubovoy's statement about pixel peeping more carefully, he seems to be implying that the print from the MFDB file is so significantly better than any crop at any enlargement viewed on the monitor, that pixel peeping is not relevant, partly because an inkjet printer has higher resolution than a monitor, and also because some printers have a slightly wider color gamut than even a good monitor.
I don't find these reasons at all credible in light of my own experiences. If the print is better than the view on the monitor (in terms of resolution at the appropriate magnification on the monitor), or in terms of color gamut which the monitor cannot display, then such differences are of a pixel-peeping magnitude.
Furthermore, Mark Segal, any 'additional' qualities you see in your 13"x19" print from an MFDB file (as opposed to a 35mm file), viewed from the distance you would read a book, will disappear from even a slightly greater distance, like 600mm, never mind 2.4 metres.
Ray,
While I could have much to tell you, for the moment I won't comment further on this post, except to make one point and to ask you a question. The point is that I'm not a wealthy person who can afford to spend this kind of money frivolously and I wasn't either an idiot or on drugs when I bought that system. The question is: have you personally had a recent opportunity to compare similar images, having high scene DR, as rendered by a high-end DSLR and a Phase-1 P40+ or P65+ back?
Mark
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Hi,
I do admit, my statement was meant to be a bit provocative!
What I mean is essentially that a print has different qualities. Tonality is something can be seen at long distance. You don't need to put the print under your noose to see that it has dense black and bright highlights. These to parameter actually define the DR of a print. The next set of parameters are tonal differentiations. None of these parameters is really dependent on viewing distance, if you have normal vision (except cataract).
Closer up and with good vision fine detail contrast, noise and other factors show up.
So, it's perfectly possible to tell apart a print with deficiency in DR (defined as black to white ratio) at long distance. Other deficiencies are only visible at short distance.
Best regards
Erik
And Erik, you have made the same sort of sweeping comment that has made me come in once again. According to you a "blind man" can tell the difference between two small prints at thirty feet. That the issue is just being able to discern between black and white in the two prints.
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Hum... Mark, have you have heard the equivalent speech done by Sony/Nikon engineers? I believe that they also describe themselves as being the best in the world at what they do. In the end these are just claims.
Figures do tell the whole story, especially when they are measured on an actual device just like DR can be. We are not talking about doggy predictions resulting from a potentially flawed theoretical model, we are talking about hard facts here.
Cheers,
Bernard
I wasn't talking about "claims", I was talking about technical explanations. And no, the kind of figures being bandied around in this thread definitely DO NOT tell the whole story. And facts are no harder then the definitions and methodologies used to establish them, which in this case obviously vary.
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What folks need to realize that photography is about perception and perception is not really the same as physics. There is always a possibility that measurements don't measure the right parameters the right way, or that they are not easy to interpret. There is always a temptation to condense all findings into a single "figure of merit", in my view it's simply a stupid approach.
I can agree with that. In the case of DxOMark, the overall "Sensor Mark" score strikes me as pretty silly, and of very little use. However drilling down into the individual test results can be useful, if you understand what they're testing.
I think the DR advantage of MFDB's over DSLR's was considerably larger in the past. And it's also a fairly easy concept to understand; if the difference is large enough it will be readily apparent in images, and of course there's the whole 16-bit versus 12-bit (whether the MF backs were truly using a full 16-bits is debatable, but that's the sort of technical detail that's easily ignored).
So the "DR advantage" of MF became part of the conventional wisdom, and was oft-repeated when the merits of MF came up in discussion/debate. But technology doesn't stand still, and the small-format CMOS sensors have improved more than their FF-CCD counterparts, so the gap has closed with regard to DR. Some people don't recognize this for whatever reason, and still bring out the "DR advantage" as if it were one of the main reasons to prefer MF; in some cases even suggesting that 2- and 3-generation old MF sensors are still vastly superior in DR to today's latest DSLR's.
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What I mean is essentially that a print has different qualities. Tonality is something can be seen at long distance. You don't need to put the print under your noose to see that it has dense black and bright highlights. These to parameter actually define the DR of a print. The next set of parameters are tonal differentiations. None of these parameters is really dependent on viewing distance, if you have normal vision (except cataract).
Differentiating pure black and paper white is not hard from a distance, I agree. Subtle tonal differentiations? I'm not so sure about that one, you have to be close enough to distinguish the regions the tones are distributed over. I think really subtle tonality would require closer examination than can be achieved from across a room.
So, it's perfectly possible to tell apart a print with deficiency in DR (defined as black to white ratio) at long distance. Other deficiencies are only visible at short distance.
All well in good if you're comparing the white and black points of various papers; but not so much if you're interested in the DR of cameras.
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Please see my Editor's Note (http://www.luminous-landscape.com/reviews/cameras/h3d50ii.shtml#update) just added to Mark's review. It will hopefully shed some light on the DR question.
Michael
Thanks Michael for this agnostic update. The next question of course is "so what of the human eye?"
If I understand correctly, although humans have a theoretical DR of about 24 stops accounting for pupil size adjustment etc. our instantaneous DR is about 10-14 stops (I picked this page (http://www.cambridgeincolour.com/tutorials/dynamic-range.htm) for reference, but there seems to be many others). If this is correct, then it means that a correctly exposed MFB photograph will match the human eye at the time a photograph is taken (10-14 stops v. 12-13 stops).
Now as an impecunious amateur, I can only dream of ever owning a $20k MFB, so can you pro users out there tell me: how far from 'the real thing' is the range of MFB? - particularly for outdoor photography.
Cheers
François
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Unless you have done a thorough measurement of the DR of your back vs that of high end DSLRs it would appear that you have believed the numbers proposed by the vendor of your back at least in absolute terms if not in relative terms compared to your previous camera. If not you may want to either present your test results, or phrase your position as an impression.
Cheers,
Bernard
Bernard,
Between DxO and Phase-1 Inc., there is a difference of numbers amounting to 0.7 of DR. One says it is 13, the other says it is 13.7. Are they measuring the same way under the same conditions, I have no idea. But the DR is way up there. As for the DSLRs, two different approaches to measurement produce very different numbers. Is this unusual? - not in the least. So we need to be careful about putting blind faith in numbers. I have not measured the DR using any of these approaches from either my Canon 1Ds3, or my Phase P40+. I have photographed the same scenes with both cameras under as near identical conditions as I could, and I can tell which has higher DR, better shadow detail and better resolution straight out of the box. You'll have to take my word for it - no sense dumbing it all down into JPEGs. As I told Ray, I don't THINK I was drugged when I bought the system. But I still like my Canon 1Ds3 a lot and I still use it a lot. It makes great images, as well it should for what it cost, but it isn't a Phase-1 P40+, thats all.
Mark
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I have not seen any evidence to suggest that a medium format back has twice as many stops DR than a top end 35mm DSLR. When it comes to DR on sensors - 1 stop is a pretty good difference - 6 or 7 is absurdly different. It's not like there's this magic sensor different for MF that only MF manufactures have and the guys that make 35mm sensors don't. Point the cameras at a decent chart, and I have an 18 stop backlit chart sitting right next to me now and let's see it.
Graeme
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I have not seen any evidence to suggest that a medium format back has twice as many stops DR than a top end 35mm DSLR. When it comes to DR on sensors - 1 stop is a pretty good difference - 6 or 7 is absurdly different. It's not like there's this magic sensor different for MF that only MF manufactures have and the guys that make 35mm sensors don't. Point the cameras at a decent chart, and I have an 18 stop backlit chart sitting right next to me now and let's see it.
Graeme
Graeme, this is exactly what makes me think that the ways in which DR is defined and measured differ between various organizations. Perhaps there is one right way of doing it, I don't pretend to know, but it seems pretty clear that what's going on here is most likely a comparison between apples and oranges. I like your idea of pointing a high-end DSLR and a Phase back at your chart and measuring DR using exactly the same method in exactly the same conditions. As Jeff Kohn said, it is the relative results which mattes, not the absolute, and that would probably settle it in a relative sense. If you don't mind, should I have an opportuity to get over to Ottawa, I shall bring the gear, look you up and we can do it. I'd love to see the outcome, whatever it reveals.
Mark
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My view is that DxO does unbiased and scientifically sound work. I certainly feel they deserve a lot of respect for publishing their results, no one else is doing a similar effort. So I'm much against DxO bashing.
Yes, indeed.
Whenever I have been able to compare DxO numbers and the results of calculations based on CCD/CMOS sensors data sheets, I've found them to be in good agreement. It is certainly possible to design a system poorly and worsen the noise part of the equation. But, on the other side, it is impossible to improve on the best result a sensor can deliver. There's nothing magical about larger sensors well depth (especially if they have a pitch that"s similar to their smaller siblings) and even if the cabling/amplifiers/DACs used in MFDB had the "magical" properties of very high end audio gear, they couldn't improve results by 6 stops. That's very obvious when those sensors are used for science and SNR or DR are really supposed to have a standard meaning. Let's not forget that improving things by a factor of "1 stop" is roughly equivalent to doubling the performance of the system, "6 stops" improve the performance of a system by a factor of 64... That's _really_ a lot.
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Mark,
I really appreciate that approach!
Best regards
Erik
...
If you don't mind, should I have an opportuity to get over to Ottawa, I shall bring the gear, look you up and we can do it. I'd love to see the outcome, whatever it reveals.
Mark
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Hi,
The original statement was by Mark Dubovoy, claiming that the differences were visible at 30 feet on a small print. At that distance tonal differences would be visible on a large scale. The original statement was about DR on paper and a small print.
Thanks for your thoughtful comments!
Best regards
Erik
Differentiating pure black and paper white is not hard from a distance, I agree. Subtle tonal differentiations? I'm not so sure about that one, you have to be close enough to distinguish the regions the tones are distributed over. I think really subtle tonality would require closer examination than can be achieved from across a room.
All well in good if you're comparing the white and black points of various papers; but not so much if you're interested in the DR of cameras.
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I just did part of the experiment. I have an 8x10 silver gelatin Ansel Adams Merced River, Autumn hanging on my wall (not an original print by Adams but by Alan Ross from the original 8x10 negative (see: this link (http://www.anseladams.com/index.asp?PageAction=VIEWPROD&ProdID=1036)). I also have a very good print from the Ansel Adams calendar. At 30 feet, they pretty much look alike. Back in the old film days when I was learning the Zone system, we were instructed to do the simple experiment of taking a picture of a uniformly colored surface with some texture, exposing it for all the Zones. The negatives were developed all under the same conditions and prints were made using exactly the same enlarger exposure and development. You end up with a series of prints of all Zones and the texture disappears at some point before you get to absolute white and black. It's of course dependent on the film of choice. I think Adams goes over all this in "The Negative" which unfortunately is over at a friend's house. From what DxO, Norman Koren and others have tested, digital SLRs have a greater dynamic range than some kinds of film but do have to be treated differently (see: Koren's good explanation (http://www.normankoren.com/digital_tonality.html))
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Graeme, this is exactly what makes me think that the ways in which DR is defined and measured differ between various organizations. Perhaps there is one right way of doing it, I don't pretend to know, but it seems pretty clear that what's going on here is most likely a comparison between apples and oranges. I like your idea of pointing a high-end DSLR and a Phase back at your chart and measuring DR using exactly the same method in exactly the same conditions. As Jeff Kohn said, it is the relative results which mattes, not the absolute, and that would probably settle it in a relative sense. If you don't mind, should I have an opportuity to get over to Ottawa, I shall bring the gear, look you up and we can do it. I'd love to see the outcome, whatever it reveals.
Mark
That's great.
Hope you guys will do it, and of course published the results here
Regards,
Fred.
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Graeme, this is exactly what makes me think that the ways in which DR is defined and measured differ between various organizations. Perhaps there is one right way of doing it, I don't pretend to know, but it seems pretty clear that what's going on here is most likely a comparison between apples and oranges. I like your idea of pointing a high-end DSLR and a Phase back at your chart and measuring DR using exactly the same method in exactly the same conditions. As Jeff Kohn said, it is the relative results which mattes, not the absolute, and that would probably settle it in a relative sense. If you don't mind, should I have an opportuity to get over to Ottawa, I shall bring the gear, look you up and we can do it. I'd love to see the outcome, whatever it reveals.
Mark
At least if the images are posted and the raws made available, people with different methodologies of DR measurement can take that data and do to it whatever they want. Those who work visually can push and pull the files in Photoshop, those who put numbers to it can do so, but with the cameras shooting exactly the same chart you can make valid comparisons. Feel free to come by and shoot charts with me.
Graeme
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Unfortunately DxO Labs has complicated matters. Their DxO Mark camera tests have become widely read by photographers around the world, and are quoted as gospel by many. Regrettably there are concerns that I, and others have expressed about some aspects of DXO's tests, and I have been in communication with them over this in the past.
The only aspect that is relevant to this discussion is with regard to dynamic range. The standard definition is, as mentioned above, how many F stops above and below middle gray can be recorded while delivering full texture and detail. The DXO definition, according to their web site, is the range between zero signal to noise and full saturation of the sensor.
This approach is not inherently flawed, it's just that it does not take into account the linear nature of sensors. It is therefore not a particularly relevant way of measuring DR to a photographer, as opposed to an engineer.
Tests done by me in the past, as well as others more recently, show that DSLRs have a dynamic range of 6–7 stops while top medium format backs are in the 12-13 stop range. This is using the common definition of DR as mentioned above.
The exact numbers are open to some debate because of the subjective aspect of the test, but usually a one stop differential is the most seen between testers or test runs. But, if someone is using a different set of criteria for their tests then obviously results can differ much more widely.
The question that this raises in my mind (as I see it) is why are DXO measuring DR by taking the difference between zero signal to noise and full saturation of the sensor? And how does this really correlate to how many F stops above and below middle gray can be recorded with full texture and detail? And further.. why is the difference in DR so great using the two different measurement techniques? And why is is DXO's methodology not relevant in the real world? (as this seems to be what is being implied).
It seems odd to me that DXO with all their scientific efforts would measure DR in a method that did not take into account the linear nature of the sensor. Its not that I am a DXO pundit - far from it. I just want to fully understand why different measuring methods are being used (as this is clearly the reason for the differences) and which (if any) actually correlates to real world results.
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At least if the images are posted and the raws made available, people with different methodologies of DR measurement can take that data and do to it whatever they want. Those who work visually can push and pull the files in Photoshop, those who put numbers to it can do so, but with the cameras shooting exactly the same chart you can make valid comparisons. Feel free to come by and shoot charts with me.
Graeme
Thanks Graeme. I shall definitely keep this invitation in mind. It won't be in the very near future because I am in Toronto and you in Ottawa, but I shall ping you when I see an opportunity to get up there, and if you're avaiable we can do that.
Mark
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The question that this raises in my mind (as I see it) is why are DXO measuring DR by taking the difference between zero signal to noise and full saturation of the sensor? And how does this really correlate to how many F stops above and below middle gray can be recorded with full texture and detail? And further.. why is the difference in DR so great using the two different measurement techniques? And why is is DXO's methodology not relevant in the real world? (as this seems to be what is being implied).
It seems odd to me that DXO with all their scientific efforts would measure DR in a method that did not take into account the linear nature of the sensor. Its not that I am a DXO pundit - far from it. I just want to fully understand why different measuring methods are being used (as this is clearly the reason for the differences) and which (if any) actually correlates to real world results.
http://www.dxomark.com/index.php/eng/Techn.../Noise-protocol (http://www.dxomark.com/index.php/eng/Technologies/Testing-protocols/Noise-protocol) shows how DXO do it - with grey targets over a 13 stop range. I actually think that's too small a range - they should be going much further from practical experience, and that's why I've just sourced an 18 stop chart rather than the 13.66 stop one I was using. Because sensors are linear and we know noise is the limit of dynamic range and that the brighter the tones the less noise they contribute to the final image, measuring SNR is a completely valid way of determining absolute dynamic range.
Graeme
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I have photographed the same scenes with both cameras under as near identical conditions as I could, and I can tell which has higher DR, better shadow detail and better resolution straight out of the box. You'll have to take my word for it - no sense dumbing it all down into JPEGs.
may we have just your raw files instead of your word ? please don't tell that you are not keeping them
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FWIW, I was curious just how much practical DR my 1Ds III has, so I did my own little test.
I shot out the window of my office using the outdoor clouds as my highlights and the indoor room setting as my base shadows. I used a Sekonic L-558 spot meter (1 degree spot) to determine the relative exposure differences between the different parts of the scene. I bracketed off a series of shots at 1/3 stop intervals to pick the shot that was closest to being overexposed without losing detail. The shot was chosen by pulling a -1 exposure compensation in LR to rescue any highlights buried the RAW data, then picking the ideal ETTR shot as my one to process. I then tried to pull up the shadows in LR using fill light and tone curves, with lots of NR and no sharpening, plus a second round of NR in Noise Ninja. The attached shot is a 50% pixel view. The masked area in the window is a -1 exposure compensation overlay, to show the highlight details in the RAW file.
Details - 1Ds III, 24-70L, f/11, 1/25, ISO 100
I would say that details are visible down to around 10 stops below the highlight, but my personal threshold would be about 7 or 7.5 stops for a quality print. I'd love to see the same sort of test from a D3X or MFDB if any of you folks have the time.
[attachment=20751:1Ds_III_DR_Test.jpg]
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I wasn't talking about "claims", I was talking about technical explanations. And no, the kind of figures being bandied around in this thread definitely DO NOT tell the whole story. And facts are no harder then the definitions and methodologies used to establish them, which in this case obviously vary.
OK, words again. How is a technical explanation proposed by one side of the chasm without neutral validaton not a claim. It only differs if you trust the source, which closes the loop of this beautiful example of circular argument, you basically trust the source because you trust the source.
For one, DxO has a very clear methodology published on their site and I garantee you that their results would have been proven wrong with similar facts if they were wrong. The fact that nobody doing similar measures has been able to show different results is a clear proof that, per the definition they use, their results are correct.
As discussed elsewhere in this thread, the relevance of their figures for actual photography is doubtful, but the same doubt applies to both the DSLR and MFDB figures, and there has been no explanation proposed as to why the gap between their figures and real world ones would have to be larger for DSLRs than for MFDB, and certainly not 6 stops larger.
Cheers,
Bernard
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Ray,
While I could have much to tell you, for the moment I won't comment further on this post, except to make one point and to ask you a question. The point is that I'm not a wealthy person who can afford to spend this kind of money frivolously and I wasn't either an idiot or on drugs when I bought that system. The question is: have you personally had a recent opportunity to compare similar images, having high scene DR, as rendered by a high-end DSLR and a Phase-1 P40+ or P65+ back?
Mark
Mark,
That's a fair question and I'll attempt to give a fair answer. There are many, many different models of cameras on the market. It would be unreasonable to expect anyone to hire each model of camera with lenses and compare performance with what they already own (or hire two camera models at a time) before making a purchasing decision.
Fortunately, we have a number of organisations which specialise in performing such tests and which make the results freely available on the internet.
I'm very well aware that larger sensors collect more light, and as a result of that fact are able to produce subtle improvements in image quality which can be clearly seen when such images (or prints) are viewed from a close distance.
For the past 5 years or so, I have owned mainly two different formats of cameras which differ in size by a degree which is just as great (approximately) as the difference in sensor area between a P65+ and a full frame 35mm. (ie. various Canon cropped format cameras plus a 5D, the 5D sensor being 2.6x the area of the Canon cropped format DSLR).
I'm no stranger to the advantages of the larger sensor. Generally the larger sensor provides higher resolution, smoother tonality, greater color sensitivity, lower noise and shallower DoF at the same f stop. These are all good reasons to buy a large-sensor camera (with the possible exception of shallow DoF).
They are the reasons why I am hesitating in choosing between a 7D and a 5D2 for my next upgrade. The 7D has the clear advantages of longer reach, lower weight, faster frame rate, possibly better autofocussing, and the 5D2 has the other advantages mentioned above.
It's interesting that the DR of the 7D appears to be just as good as the DR of the 5D2, up to ISO 400. Beyond ISO 400 both the old 5D and the new 5D2 outshine the 7D, but not by a huge amount. At most by a full stop or slightly less. Nothing like the magnitude of the DR differences between 35mm and MFDB that Mark Dubovoy claims.
Another important point which is so often overlooked when comparing image/print quality is viewing distance.
Anyone who views a print from a closer distance than 1.5x its diagonal could be considered a pixel peeper. No harm in that . But I really question the wisdom of spending huge amounts of money on equipment which produces superior image quality which is discernible only from a pixel-peeping distance, or a closer distance than is required to appreciate the composition as a whole.
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OK, words again. How is a technical explanation proposed by one side of the chasm without neutral validaton not a claim. It only differs if you trust the source, which closes the loop of this beautiful example of circular argument, you basically trust the source because you trust the source.
For one, DxO has a very clear methodology published on their site and I garantee you that their results would have been proven wrong with similar facts if they were wrong. The fact that nobody doing similar measures has been able to show different results is a clear proof that, per the definition they use, their results are correct.
As discussed elsewhere in this thread, the relevance of their figures for actual photography is doubtful, but the same doubt applies to both the DSLR and MFDB figures, and there has been no explanation proposed as to why the gap between their figures and real world ones would have to be larger for DSLRs than for MFDB, and certainly not 6 stops larger.
Cheers,
Bernard
Bernard, there is no circularity, and it's not just words. There's a difference between advertising, where the advertiser simply tells you they have best sliced bread on earth and you take it or leave it, versus a technical seminar where a number of things are explained (to the extent they are prepared to reveal) about the kinds of factors which go into their sensor technology. What really stuck in my mind about this session is that truly a great deal of stuff goes into the design of the hardware and the software of this technology, so as I pondered your comment about being able to rely on the numbers, it simply struck me that the very limited set of numbers being discussed in this threadd are not a sufficient basis to conclude on anything decisively. Like you, I too believe in relying on objective, quantifiable factors as much as I can, and when it comes to photography in particular, I also believe in my eyesight. But returning to the numbers, as you well know, there are numbers and there are numbers. Every aspect of the design of a sensor and its firmware can be described in terms of measurements and numbers, and there must be a great many of them that only sensor design technologists would know. I would speculate that when comparing sensors, numerical differences (or even the presence or absence) of some of these variables would have more critical impact on driving differences between results than others. And only the designers would know that too. In fact. most of us probably don't know what we don't know about this business. So we can be "scientific" and pretend that the few numbers we know and can relate to are a sufficient basis for drawing conclusions, or we can simply acknowledge that maybe we don't know enough about which numbers (in combination) matter most, so perhaps better trust our eyesight and rely on what impresses us as makers of images.
As for DxO, some of it may be more or less relevant to actual photography as the case may be. It's not clear in my mind what the gap is between "their figures" and "real world ones", because I don't know what you mean by "real world ones". If you are alluding to the issue that different ways of measuring things produces different results, and more so for one technology than the other, let me take a stab at what the situation may be. The firms who claim that their stuff produces 7 stops of DR are measuring it using their own definition and methods. DxO and MF firms which claim that their stuff produces 13 stops of DR may be using a different definition and approach. So what's missing are sets of measurements for both technologies using both sets of definitions and methods. That may be the gap which needs to be filled. When that's done, I suspect that differences of 6 f/stops will shrink radically. And even if it does, what my eyes tell me will still be what my eyes tell me!
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How to test dynamic range in a meaningful way has always been a contentious issue. From the perspective of the practical photographer, I would suggest that the usefulness of a high DR lies in the capacity to extract meaningful image quality from the darker shadows without the necessity of clipping the highlights with overexposure in order to do that.
Some years ago, Jonathan Wienke devised a Dynamic Range Chart for this very purpose. The principle is, the legibility of text or numbers is an excellent way to define 'meaningful image quality'. If anyone wants to compare the resolution of two lenses (using the same camera), the lens that produces legible text in circumstances where the other can't, is the sharper lens. What could be more meaningful than that?
I used Jonathan's chart to test the DR of my 5D, some years ago. From memory, it was about 11 stops. In other words, I was able to take 11 exposures, each exposure half of the previous one, yet was still able to discern some detail in the 11th, extremely underexposed shot.
Of course, with such a method, the initial exposure is critical to the accuracy of the results. One has to aim for a true ETTR with the first shot, with each camera tested.
Any argument about the significance in practical terms of the discernible detail in the lowest exposure, is irrelevant. The essential point is that the same methodology should be used with each camera tested.
Confusion about DR specs tends to arise only when different methodologies are used when testing different cameras. I tend to place more faith in DXO Mark results than verbal pronouncements from owners of MFDB systems who refuse to show their DR comparisons, because DXO employ a consistent methodology with all the cameras they test.
Here's a jpeg compression of a downsized chart created by Jonathan Wienke. It could no doubt be elaborated upon and improved by someone interested in such matters. I'm currently too busy building retaining walls at the back of my new house.
[attachment=20753:Test_target.jpg]
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One thing to remember is that there can be other factors than the sensor, not least the lens and the development software / algorithms and gamma curve design that can dramatically effect the perceived dynamic range of an image. That is why it's important to measure with a common methodology.
Even when that measurement is done, and say it's done in a way that produces a very large number, much larger than you feel is right for that camera, then that is most likely your personal noise tolerance at work, along with your own image development methodology. Once you can factor in a value for those, you can take the measured number and subtract your factor and use that for how you want to meter / light / expose.
Graeme
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Anyone who views a print from a closer distance than 1.5x its diagonal could be considered a pixel peeper. No harm in that . But I really question the wisdom of spending huge amounts of money on equipment which produces superior image quality which is discernible only from a pixel-peeping distance, or a closer distance than is required to appreciate the composition as a whole.
Ray, OK, let me confirm that if I had to pixel-peep to appreciate the IQ from a Phase-1 back I wouldn't have spent my precious dollars on it. There is a richness of tonality, shadow detail and resolution which comes through whether the print is 11*17 or 27*36 and in both cases viewed at distances appropriate for seeing the whole picture as it was meant to be seen. Much as I really like what I get from my Canon 1Ds3 and I shall continue to use it as well, the Phase produces a higher quality of image with the bonus of lots more potential for huge amounts of enlarging or cropping while still preserving great resolution and tonality. So I look upon it as a tool for growing with - moving into a different style and type of image making. One of the nice things about a good DSLR is that we can use it almost like a sophisticated point-and-shoot and obtain terrific results. That's much harder to do with an MF set-up because it's more demanding to get the maximum of the resolution it can deliver. So one uses different things in different ways for different purposes - as usual.
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may we have just your raw files instead of your word ? please don't tell that you are not keeping them
You needn't tell me what not to tell you, because I'll tell what I have to say regardless, and the answer for now is NO. But in the fullness of time it may be YES.
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One of the nice things about a good DSLR is that we can use it almost like a sophisticated point-and-shoot and obtain terrific results.
So true and without this you wouldn't see art directors and models stepping in and calling themselves professional photographers.
I'm really glad there is a tremendous difference between DSLRs and medium format digital backs. The best research is being done by companies like P1 and that will trickle down for the rest of us.
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I agree Bernard.
I read your posts carrefuly, and you certainly point some interesting details. But in another topic (about the pentax MFD), you assumed that the 645D could be a game changer. Maybe I did not understood in what way or context you pointed that fact, and how could it be a game changer in the current panorama.
Well, assuming that the current talk about MF sensors being that much superior DRwise is actually true, don't you think that such miracle technology available for 6500 US$ would be game changing?
Wait... it is actually already available in second hand P45 for no more than 9.000 US$. You got to wonder why both sellers and buyers have aligned their prices with high end DSLRs although they remain that superior...
I simply think that in these kind of debates, there is fast much more writings and concepts that images, in a website dedicated to...image. So what happen is that we have an incredible amount of arguments but very little real life images in order to endorse the arguments. Yes, a lot of graphics.
Well, many of the people in this thread are known for their excellent photographs. They managed to take excellent photographs with slide film also, and don't appear to have changed their style that much... although they gained a huge 5 stops of DR.
As far as my selfish self is concerned, you will find a few images here. http://www.flickr.com/photos/bernardlanguillier/ (http://www.flickr.com/photos/bernardlanguillier/)
Most shot with a DSLR (SLR/n, D2x, D3 and D3x in the past 15 months), some shot with a Mamiya ZD in those days where I was still a believer in some form of MF black magic.
Cheers,
Bernard
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This is a fascinating discussion and I am eager to see the evidence that MF DR exceeds DSLR (in my case a D700) by 6 stops. So far I have heard a lot of rhetoric from MF DR defenders but little else.
Mark says "The dynamic range of a typical high-end professional 35 mm DSLR is around 7 F/stops. Medium Format cameras are closer to 13 F/stops of dynamic range. You can see the difference from 30 feet away in a small print."
Michael says "Tests done by me in the past, as well as others more recently, show that DSLRs have a dynamic range of 6–7 stops while top medium format backs are in the 12-13 stop range. This is using the common definition of DR as mentioned above."
Mark Segal, playing coy, says about presenting files with evidence: "You needn't tell me what not to tell you, because I'll tell what I have to say regardless, and the answer for now is NO. But in the fullness of time it may be YES."
I must say that I always felt LL was the reliable source but it is a real test of credibility to make a claim of 6 stops, a huge difference, without presenting the evidence. I hope it is forthcoming. Two raw files, one from a top end DSLR, ideally a D3x and one from a MF of a indoor/outdoor scene, with huge DR, and measured EVs would convince me one way or the other.
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Mark Segal, playing coy, says about presenting files with evidence: "You needn't tell me what not to tell you, because I'll tell what I have to say regardless, and the answer for now is NO. But in the fullness of time it may be YES."
No, I don't play coy - ever. What I tell you is where it's at and I have my reasons. Full stop.
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Interesting that there is no discussion of light intensity, contrast ratios or bit depth.
http://www.cambridgeincolour.com/tutorials/dynamic-range.htm (http://www.cambridgeincolour.com/tutorials/dynamic-range.htm)
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With all the talk of dynamic range haven't you missed the elephant in the room. Just look at the CA/blue fringing on the Hasselblad picture in figure 3.
[attachment=20755:blue_fringing.jpg]
Am I seeing something that you aren't?
Cheers,
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With all the talk of dynamic range haven't you missed the elephant in the room. Just look at the CA/blue fringing on the Hasselblad picture in figure 3.
[attachment=20755:blue_fringing.jpg]
Am I seeing something that you aren't?
Cheers,
I see blue fringing with my Hasselblad back under similar conditions. An example:
Steve[attachment=20757:__1_of_1__5.jpg]
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the development software / algorithms and gamma curve design that can dramatically effect the perceived dynamic range of an image.
well, we can use CaptureOne in both cases... but so many great photogs here, equipped w/ the state of the art everything and yet not capable to post a couple of raw files (dslr + mfdb) to back up the claims... what an ultimate shame ... I posted the question @ PhaseOne forum - let us see if the manufacturer will backup the customers
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aren't they putting microlens (even in gapless design) on top of the surface to direct the light to those "actual light sensitive areas", are they ?
I will admit to little actual first hand knowledge of this, but from what I've been led to believe (and is supported by this article (http://www.cambridgeincolour.com/tutorials/camera-sensors.htm) ), the micro lenses are not lenses in the sense of focusing light, but instead redirect light that would normally fall on the wasted area between sites in to a site. As such I don't believe they have the ability to focus the light on the specific area of the site that is light sensitive.
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I see blue fringing with my Hasselblad back under similar conditions. An example:
Steve[attachment=20757:__1_of_1__5.jpg]
The fringing reminds me of my Fuji F10, the painterly effect of the Kodak SLRn...
Cheers,
Bernard
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Here's my take. So far I have not been able to identify a constant and ominpresent correlation of sensor measurments with the actual visual appearnce of a printed photograph. (The stress is on constant and omnipresent) Using the the highly critized 50D for example, I do sometimes see superior noise perfomacne to other cameras in certain circumstances while I see inferiror results in others. Evaluation results depend to a large degree on how and how much you process an image to reach the desired final result. They also depend on light conditions (The 50d outperforms many cameras when I use ISO 1600 in good light but is vastly inferior to them when i use such high isos in low light)
Shooting alongside colleagues with middle format cameras, I have seen theses cameras to be vastly superior to a dslr in some circumstances and for some images and about equal in others. I concluded that any technical discussion about measurments doesnt help in any way when you want to know whether your photography requires a particulr type of camera. You have to go out and shoot different subjects, and see whether any theortical advantage translates to practically relevant differences.
All you need to know is that medium format digital may give superior results. This information is enough to include such cameras in ones own evalutaion. Measurments might just do the opposite, they may steer you away from a camera that might deliver the best image quality for your subjects even though it is not worse than others according to some measurments. As micheal pointed out, measurments are never objective because the measuring conditions are determined and pre-set subjectivly. If the measuing conditions do not reassemble your shooting conditons they are almost worthless to an individual photographer. This is why even the scientificly best executed camera evaluation is in no way a replacment for individual real life tests. And even so being thoroughly executed by the most highly respected technician or scientist labortory measurments might not even be a good guidance for your own use of the camera, depending on how the tests where done.
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Well, assuming that the current talk about MF sensors being that much superior DRwise is actually true, don't you think that such miracle technology available for 6500 US$ would be game changing?
Wait... it is actually already available in second hand P45 for no more than 9.000 US$. You got to wonder why both sellers and buyers have aligned their prices with high end DSLRs although they remain that superior...
Well, many of the people in this thread are known for their excellent photographs. They managed to take excellent photographs with slide film also, and don't appear to have changed their style that much... although they gained a huge 5 stops of DR.
I have no idea about the true difference of the DR between a DSLR and MF back, but when someone claims a 6 stop advantage to the latter without any hard evidence presented, I begin to suspect cognitive dissonance (http://en.wikipedia.org/wiki/Cognitive_dissonance).
Not saying that is the case here, but extraordinary claims normally demands extraordinary evidence. And some sort of evidence should be presented to support the claim in this case.
Ronny
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I wouldn't have thought I'd dare to intervene in a MFDB-vs.-MFDB thread... but as this is mostly about dynamic range I'd throw in the 2 (euro) cents of a cheapskate only shooting with a goodol'300D (yeah, the original DRebel ; some results in the link below in my signature).
First, the theoretic definition of sensor DR as difference between saturation and noise floor is theoretically correct... But the difference between theory and practice is greater in practice than in theory, isnt' it?
Where perception kicks in is in the noise structure : with the same measured Signal to Noise Ratio, a perfect gaussian noise on one side will be far more acceptable, photographically speaking, than the same noise only made of banding (that fugly orthogonal pattern in noise, very evident in some cases with my camera).
I'd really like to stress that one : banding noise shall also be measured in a way or another, besides noise. That can also be applied to other structures of noise, as eg the "noise blotching" (color noise splattered on a few pixels) of some P&S sensors (though that is a bit farther from the topic).
Second, I'd say there is yet another factor in real-life DR, especially when dealing with large ranges above 10 stops : lens veiling (sometimes called flare - I'm not talking about the colored artifacts showed with a point light source near or in the field, but about the general contrast reduction caused by light scattering in the lens or sensor chamber).
This parameter can be offset by shooting the same low-contrast target in a dimmer environement with + and - exposure correction, but in a real world image, the whole thing is about to capture shadows and highlights in the same shot, so veiling can also be there.
In a first time, lens veiling could improve the ability to record high DR scenes, as it levels up the shadows (it was a darkroom trick in the form of preexposure if I remember well).
However, with deeper shadows, it doesn't only level up the tonality but decreases contrast, to the point that initial texture is drowned in a grey veil, and so it could also limit DR.
I've encountered this phenomenon while playing with modern raw files (see link below) : sometimes while pulling up the shadows, it only brings an uniform grey before bringing up objectionable noise.
Third, about marketing claims vs. facts : the "playing with raw files" was actually a game on a french forum (http://www.chassimages.com/forum/index.php/topic,67792.0.html) (link in french with MANY side discussions), where someone (some here may know Thierry Legault (http://apod.nasa.gov/apod/ap090516.html)?) took some raw files of various origins and zeroed the N least significant bits, effectively converting them into 14bits to 8bits raws.
Bottom line : no reasonably visible difference past 10 bits, no pixel-peeping significant difference past 12 bits, even with MFDB files (MFDB pages 7-8-9, note that the first test on page 1 had a 2bit bias). There is just plain noise in the last bits, as said elsewhere (http://theory.uchicago.edu/~ejm/pix/20d/tests/noise/noise-p3.html#bitdepth). However, I suspect now that in some cases the veiling might limit the DR too much.
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Well, assuming that the current talk about MF sensors being that much superior DRwise is actually true, don't you think that such miracle technology available for 6500 US$ would be game changing?
Wait... it is actually already available in second hand P45 for no more than 9.000 US$. You got to wonder why both sellers and buyers have aligned their prices with high end DSLRs although they remain that superior...
Well, many of the people in this thread are known for their excellent photographs. They managed to take excellent photographs with slide film also, and don't appear to have changed their style that much... although they gained a huge 5 stops of DR.
As far as my selfish self is concerned, you will find a few images here. http://www.flickr.com/photos/bernardlanguillier/ (http://www.flickr.com/photos/bernardlanguillier/)
Most shot with a DSLR (SLR/n, D2x, D3 and D3x in the past 15 months), some shot with a Mamiya ZD in those days where I was still a believer in some form of MF black magic.
Cheers,
Bernard
Ok, Bernard.
I know your portfolio. My points of course where not directed to you personaly but in general. When I was talking about the lack of images I was not thinking of directing people to one's wesite to see his beautiful pictures. Let me explain myself:
This topic has been on and on for ages now, and as soon as there is a possibility, the forum (or the forums) is in flame.
There are clearly 2 gangs but in general "dslr-band" are very sensitives with the asumed superiority of MF in terms of IQ and tend to react with more passion.
In both bands, there are knowledgable and experienced photographers and I have no doubt that you are one of them.
But then, both bands contradict themselves constantly and one of the weapon most used is DxO. Others are kind of home-made physical tesis.
As a spectator because I'm not technicaly competent, and in desire for reliable information, these endless contradictions are bringing more confusion, and I'm sure I'm not the only one who feel it.
Many points are interesting, truly I learn a lot of technical aspects but at the end there is no sensation of information but passion.
I thought that Michael's note would have brought more light, but it just reactivated the war and arguments against MF superiority.
So, imagine you start photography and see this. What would you think? Simply that it is a real mess.
That is where the idea of ilustrating arguments with 100% images is coming.
Jenbenn just put an interesting nuance in his post and it is indeed what I think.
Why did I say that I tend to trust more Michael and some other members here than a lot of dslr posters? Not because the others are not good photographers and I give my respect to everyone. BUT, and it is an important "but", because I know that Michael is using daily both systems and prints a lot from these 2 systems. That is the point Jenbenn has made: daily; and I do think he is right.
So I do not see why Michael would put a note in his web, that it his seen worldwide, confirming the DR superiority of MF if he was not sure, or at least if the real field experience would not have demonstrated such a fact.
But then, this reactivated the flames.
In that context, the idea to make a real test, in real working conditions between 35mm and MF is not that stupid I think. But with downloadable 100% files.
I'm particularly interested to see the 2 systems in different situations with texture, complicated patterns, uncontroled light outdoor and studio shots and see how they performs. Such an intensive test would bring a real therapy to the photography community all over the world and hopefully will end these showers of graphics and DoX testings.
To conclude, I do not understand why there is such a separation: If I could now, I would own both systems and use them according to my needs, desires and according to what they are best at.
Regards,
Fred.
ps: if you read french, let me note that there is a dedicated french website, and they are serious, about high resolution photography here (http://www.galerie-photo.com/)
In any case they talk about 35mm dslr, only usable for them for field pre-reportage. I suspect them to be kind of integrists and purist but there is no way they consider the 35mm at the level of MF. They just ignore complitely these gears. I imagine that if 35mm had reach such a point, they would have put a kind of "alleluia" note.
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I'm not going to fan the flames any more than needed, but I can't resist making one more comment in support of Fred's.
The world-wide market for medium format backs is approximately 7-8,000 units. That's all manufacturers combined.
These devices (with camera body and a couple of lenses) are priced in the $30–$50,000 range U.S. As Mark pointed out in his essay, that's the cost of a current luxury car.
One more factoid: About 70% of MF systems are bought by working professional photographers, the rest by fine art photographers and wealthy amateurs.
Here's the point. For the pros an MF system is a tool for earning their livelihood. It is purchased with the intention of helping them make money. No person would spend a good chunk of a year's income on a tool that did not offer an advantage. In my experience every pro that I know (and I know quite a few around the world) has done their own exhaustive comparisons and test, not relying on web site chatter, magazine reviews and online tests.
The fine art photographers are in a similar boat. They too make their livelihood (or a good part of it) from exhibiting and selling their prints. If a $1,000 to $6,000 DLSR gave them what they needed, why on earth would spend $30-$40,000 on a back?
As for the wealthy amateurs, I'll just say that it my experience (having taught and worked with several thousand folks like this over the years on my workshops and tours) I have yet to meet one who wasn't a savvy business person who understands the value of a dollar. Like the pros and the fine art guys, they spend that kind of money for an MF back because they believe that it will provide them with a tool that allows them to produce superior quality images. And if you speak to the people at major VARs who sell this gear, you'll learn that the amateurs are often even more demanding as customers than pros.
So, where does that leave us? Are all, or even most of the people that buy medium format equipment fools, willing to spend their hard-earned money chasing a chimera, or simply looking to boost their egos regardless of cost? I don't think so, and it seems to me that anyone that does, simply hasn't taken the time to do a simple side-by-side comparison for themselves.
Frankly, there is no argument, only lack of knowledge and experience, or living in denial.
Michael
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Ok, Bernard.
To conclude, I do not understand why there is such a separation: If I could now, I would own both systems and use them according to my needs, desires and according to what they are best at.
Regards,
Fred.
ps: if you read french, let me note that there is a dedicated french website, and they are serious, about high resolution photography here (http://www.galerie-photo.com/)
In any case they talk about 35mm dslr, only usable for them for field pre-reportage. I suspect them to be kind of integrists and purist but there is no way they consider the 35mm at the level of MF. They just ignore complitely these gears. I imagine that if 35mm had reach such a point, they would have put a kind of "alleluia" note.
Fred,
OK, fair enough.
I personnally have no problem with the idea that a 40.000 US$ back might have a bit more DR than the camera I use.
This whole thread is a reaction to the totaly unreasonnable assumption that the gap is huge, and to the lack of rigor of the explanations to support these statements. I am reacting more as an engineer than as a DSLR owner who would be afraid to lose whatever fight. For my applications I would not buy a back even if it cost less than my D3x, and I really mean it.
Et oui, je suis francophone et les liens m'interessent, merci.
Cheers,
Bernard
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There are clearly 2 gangs but in general "dslr-band" are very sensitives with the asumed superiority of MF in terms of IQ and tend to react with more passion.
IQ is a vast subjective topic and can be debated forever. Lenses do play a non-negligible role <G>
But as far as sensors capabilities are concerned, it is actually very simple, convenient because 1 stop essentially equals 1 bit.
Looking at the H3DII 50 for example, it is known that it uses the KAF-50100 sensor. The sensor characteristics are available here
http://www.kodak.com/global/en/business/IS...138/13219/13220 (http://www.kodak.com/global/en/business/ISS/Products/Fullframe/KAF-50100/specs.jhtml?pq-path=11937/11938/12138/13219/13220)
It saturates at 40300e and has a read noise of 12.5e for a 70.2 db dynamic range.
Checking the specs with the very simple formula given here (a manufacturer of scientific CCD products)
http://www.ccd.com/ccd111.html (http://www.ccd.com/ccd111.html)
40300 / 12.5 = 3224 (in other words, basically right between 11-12 bits/stops)
log (3224) = 3.508...
3.508 * 20 = 70.167 db
What is the measured DxOMark?
http://www.dxomark.com/index.php/eng/Image...elblad/H3DII-50 (http://www.dxomark.com/index.php/eng/Image-Quality-Database/Hasselblad/H3DII-50)
11.5 stops.
A DSLR with 5.5 stops (6 less) would just be able to produce posterized jpegs.
If you want to gain stops, and you reduce read noise to 1 e instead of 12.5 e, you've gained 4 stops. You should still work on well capacity, which can't really be increased unless you move to larger pixels or different processes. Anyway, Hasselblad is stuck with the Kodak sensor and will not improve read noise, so the point is a bit moot.
One factor that plays in favour of MFDBs, if you compare it to a DSLR in a print that has the same physical size, is that some relative binning occurs since the MFDB has more pixels. This is a good thing, but it won't give a 6 stops improvement unless the number of pixels are drastically different.
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As discussed elsewhere in this thread, the relevance of their figures for actual photography is doubtful, but the same doubt applies to both the DSLR and MFDB figures, and there has been no explanation proposed as to why the gap between their figures and real world ones would have to be larger for DSLRs than for MFDB, and certainly not 6 stops larger.
I think this greatly summarizes the whole issue.
It would probably be unfair to put too much weight on the claimed 6 stop difference since Mark Dubovoy says he did not do any quantitative comparison. But Bernard's argument is still valid even if it is about just 5 stops of course.
Greetings,
Christoph
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A claimed 6 or 7 stop difference is a vast difference - a 42db increase in SNR. It's not something small or trivial. It's not something that should need measuring, but measuring it should produce an utterly un-ambiguous result. It's also a very easy thing for a camera manufacturer to demonstrate with a fairly affordable calibrated backlit chart. Dalsa, a sensor manufacturer and supplier to MF backs lists their 36x48mm 48MP CCD sensor as a SNR of 74db - 12.33 stops in other language. This is very much the dynamic range of a top end image sensor for photographic applications. This either means that Canon and Nikon etc. have a 74db-42db = 32db sensor, which is utter rubbish, or they too have a ~74db sensor in their cameras, which from measuring them on charts I can well believe. Now, as I mentioned above, there's a number of image processing and lens factors that can effect the appearance of the DR, but if we're just talking sensors here, I'm very confident that MF backs don't have a 6 or 7 stop advantage.
Graeme
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Et oui, je suis francophone et les liens m'interessent, merci.
Cheers,
Bernard
Interesting topic here: http://www.galerie-photo.com/service-tirag...nt-lafolie.html (http://www.galerie-photo.com/service-tirage-laurent-lafolie.html)
about a japanese paper for prints: Tengusho.
it seems that this paper has exceptional qualities. I did not know it.
But that would be a topic for another forum room.
Cheers,
Fred.
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I'm not going to fan the flames any more than needed, but I can't resist making one more comment in support of Fred's.
The world-wide market for medium format backs is approximately 7-8,000 units. That's all manufacturers combined.
These devices (with camera body and a couple of lenses) are priced in the $30–$50,000 range U.S. As Mark pointed out in his essay, that's the cost of a current luxury car.
One more factoid: About 70% of MF systems are bought by working professional photographers, the rest by fine art photographers and wealthy amateurs.
Here's the point. For the pros an MF system is a tool for earning their livelihood. It is purchased with the intention of helping them make money. No person would spend a good chunk of a year's income on a tool that did not offer an advantage. In my experience every pro that I know (and I know quite a few around the world) has done their own exhaustive comparisons and test, not relying on web site chatter, magazine reviews and online tests.
The fine art photographers are in a similar boat. They too make their livelihood (or a good part of it) from exhibiting and selling their prints. If a $1,000 to $6,000 DLSR gave them what they needed, why on earth would spend $30-$40,000 on a back?
As for the wealthy amateurs, I'll just say that it my experience (having taught and worked with several thousand folks like this over the years on my workshops and tours) I have yet to meet one who wasn't a savvy business person who understands the value of a dollar. Like the pros and the fine art guys, they spend that kind of money for an MF back because they believe that it will provide them with a tool that allows them to produce superior quality images. And if you speak to the people at major VARs who sell this gear, you'll learn that the amateurs are often even more demanding as customers than pros.
So, where does that leave us? Are all, or even most of the people that buy medium format equipment fools, willing to spend their hard-earned money chasing a chimera, or simply looking to boost their egos regardless of cost? I don't think so, and it seems to me that anyone that does, simply hasn't taken the time to do a simple side-by-side comparison for themselves.
Frankly, there is no argument, only lack of knowledge and experience, or living in denial.
Michael
All of this makes perfect sense Michael.
However, I still believe there is more than a little amount of hypocricy and double-talk going on in these reviews. I am of the consensus that many of these reviews are made to deliberately "stir controversy" (ala Ken Rockwell), rather than to be 100% factual. And here is what I mean:
I believe it was last year sometime that you yourself wrote an article comparing (of all things) the Canon Powershot G10 to a MF P65 ... where in you yourself stated that (under ideal conditions) the little point-n-shoot Canon was able to take photographs that were so compelling that, at smaller sizes, they "could not be distinguished" from identical photos made by the P65.
You did write such an article, didn't you Michael? I believe several members here will recall this fact. I further recall that this wasn't just your experience; no, you claimed you had 20 (or was it 30?) "top professionals" view several printed images you made with the little point-n-shoot Canon ... and compared them to identical printed images made with a top-end MF back ... and that "none of you could reliably tell the difference" up to a certain size image. And that was looking at them up close.
And now here we are reading another fellow's claim (Dr. Dubovoy's) that states the exact opposite, namely that (forget a P&S) anyone should be able to see the difference between a MF image compared even to the highest-quality DSLR, on small prints, and that this clear and unambiguous difference can be seen from as far as 30 feet away! And here you are, Michael, backing-up Dr. Dubovoy.
Now, I have nowhere near the technical acumen of you distinguised gentlemen, at least not as far as photography goes, but I do recognize inconsistent statements and postures when I read them. So I am wondering, Micheal, how can you say out of one side of your mouth (last year) that neither you, nor 30 "top professionals" could reliably differentiate between P65 images and PowerShot G10 images last year (when both were taken under ideal conditions) ... and yet this year your position is that ANY professional can easily distinguish the image quality of a P65 image and a top-level DSLR image from as much as 30' away?
How can you say both statements and have them both hold water?
Or is the real truth something more like, when Canon butters your bread on a review that even their P&S cameras can favorably-compete with a MF back ... but when the MF companies butter your bread, nothing can compare to them ... even the best DSLRs ... on even the tiniest of images ... and even from 30' away?
I don't mean to be disrespectful, but the above paragraph is the only conclusion that makes sense to me, given the absolute incongruity of the two postures.
Jack
PS: I can absolutely tell the difference between a photo taken with a G10 and a P65 ... and even from most DSLRs ... but not on tiny images and certainly not from 30' away. At some point, a person has to call "bullship" and ask that some accountability to be given for all of these purely subjective (and absolutely self-contradictory) extremist positions.
.
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Frankly, there is no argument [...]
For me either, there is no argument that MFDBs costing almost as much as my previous flat do have an edge in IQ.
The debated question is why...
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For me either, there is no argument that MFDBs costing almost as much as my previous flat do have an edge in IQ.
The debated question is why...
6 or 7 stops is not an edge, it's a modern tank against bows and arrows.
The question is indeed "why?". What measurable parameters of the resulting image are superior, and by what amount.
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I will admit to little actual first hand knowledge of this, but from what I've been led to believe (and is supported by this article (http://www.cambridgeincolour.com/tutorials/camera-sensors.htm) ), the micro lenses are not lenses in the sense of focusing light, but instead redirect light that would normally fall on the wasted area between sites in to a site. As such I don't believe they have the ability to focus the light on the specific area of the site that is light sensitive.
so why bother to put the microlenses at all if they don't increase the amount of light hitting the light sensitive area... so albeit not ideally they still increase the amount of light reaching the needed place.
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Frankly, there is no argument
still no raw files, sir...
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John,
There is nothing dishonest going on; and yes, I stand behind both positions.
How is this possible? Simple. Many things in life are ambiguous, and a tiny change in beginning state can lead to a huge difference in end state.
It was Fitzgerald who wrote, "Intelligence is the ability to hold two opposing ideas in mind at the same time and still retain the ability to function."
In the case of the G10 vs Phase article most of the "trained observers" couldn't see the difference in 11X17" sized prints between the two cameras. But, of note is that there were a few who could. How? Because they didn't look at sharpness alone. They looked at depth of field, tonal accuracy, dynamic range and several other characteristics (including some that are hard to name) that gave the game away. Even pros can be mislead.
There has been more than one person comment that they can tell just by looking at my Home Page shots which have been taken with MF and which with other cameras. In an 800 pixel image this simply shouldn't be the case. But it is easily the case for those with a good eye.
I could go on, but won't. In the end what I've seen over the years (decades) of doing and teaching photography is that nailing down the question of image quality is a slippery fish. Just when you think you've got a grip, it pops out of your hands.
I guess that I'll simply continue my life knowing that photography, as with life itself, is full of contradictions.
Michael
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The question that this raises in my mind (as I see it) is why are DXO measuring DR by taking the difference between zero signal to noise and full saturation of the sensor? And how does this really correlate to how many F stops above and below middle gray can be recorded with full texture and detail? And further.. why is the difference in DR so great using the two different measurement techniques? And why is is DXO's methodology not relevant in the real world? (as this seems to be what is being implied).
If you shoot to the right, as you should with digital capture, middle gray (18% sensor saturation) is 2.47 stops under saturation, and this would be about the same with any digital camera. The rest of the DR is in tones below mid gray, and it does not make sense to use middle gray as a reference point. Digital cameras with high DR achieve it in the shadow part of the image. For a tabular presentation of these relationships see here (http://www.pochtar.com/gamut_view/gamma.htm). Where you place the noise floor determines the relative contributions of shot noise and read noise to DR. A sensor with large pixels but a poor read noise would look better if you placed the noise floor relatively high. These relationships are demonstrated interactively by this Nikon Microscopy (http://www.microscopyu.com/tutorials/java/digitalimaging/signaltonoise/index.html) Java tutorial.
The engineering definition of DR (full well/read noise) places the noise floor for DR quite low and the signal:noise here would not be useful for photography. For practical photography, one would place the noise floor higher, but a camera with a good DR at zero signal would also have a good DR 10 stops from saturation. Indeed, the per pixel random noise characteristics of a digital camera can be modeled quite well by taking only shot noise and read noise into account as demonstrated by Roger Clark (http://www.clarkvision.com/articles/evaluation-1d2/). Using these data, you can place the noise floor wherever you want. Pattern noise such as banding has to be dealt with separately if it is significant.
[attachment=20759:NoiseModel.gif]
It seems odd to me that DXO with all their scientific efforts would measure DR in a method that did not take into account the linear nature of the sensor. Its not that I am a DXO pundit - far from it. I just want to fully understand why different measuring methods are being used (as this is clearly the reason for the differences) and which (if any) actually correlates to real world results.
The sensor is linear, but the eye and photography are logarithmic. That is just how things are. But one can easily convert to f/stops using logarithms to the base two (for photography) or log base 10 for conversion to decibels as is done in engineering. What is your problem here? DR can be expressed in linear terms or log terms, but the underlying ratios are the same. For example, for the 1DMII at ISO 100, the full well is 53,000 electrons and the read noise is 16.61 electrons, giving a DR of 53,000/16.61 = 3193:1. In terms of f/stops this is log base 2 (3193) = 11.6 f/stops. If you want a S:N of 10:1 for your shadow cutoff, the DR would be 53,000/21.98 or 11.2 stops. Read noise is still predominant at this exposure. If you wanted noise floor with S:N of 30:1, the DR would be less and shot noise would predominate at this level.
Placing the noise floor relatively high might favor a MFDB since they collect a lot of photons dues to their large sensor size and have relatively poor read noise as compared to current high end DSLRs (at that is what I understand--data are hard to come by). A lot of this confusion could be cleared up if the MFDB owners would upload a raw image of a Stouffer wedge and an image with the lens cap on the camera for an estimate of read noise. Why do they not do this?
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A lot of this confusion could be cleared up if the MFDB owners would upload a raw image of a Stouffer wedge and an image with the lens cap on the camera for an estimate of read noise.
Absolutely correct. That would be exactly what is needed. However, Stouffer tops out a just over 4 OD, and I'm now using an over 5 OD chart so as to fully ensure I'm not missing anything in the noise floor. So on a Stouffer, I shoot a bracket of exposures to ensure I can see the full range.
Graeme
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Interesting topic here: http://www.galerie-photo.com/service-tirag...nt-lafolie.html (http://www.galerie-photo.com/service-tirage-laurent-lafolie.html)
about a japanese paper for prints: Tengusho.
it seems that this paper has exceptional qualities. I did not know it.
But that would be a topic for another forum room.
Thanks Fred, very interesting indeed. And for sure much more relevant than the assumed DR advantage of these magical backs.
Cheers,
Bernard
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And now here we are reading another fellow's claim (Dr. Segal's) that states the exact opposite, namely that (forget a P&S) anyone should be able to see the difference between a MF image compared even to the highest-quality DSLR, on small prints, and that this clear and unambiguous difference can be seen from as far as 30 feet away! And here you are, Michael, backing-up Dr. Segal.
Jack
Jack - let me correct this - there are two Mark's active in this discussion - the writer of the article who is Mark Dubovoy with a PhD, and then a member of the discussion audience - me - Mark Segal, who does not sport a PhD. I did not make any statement to the effect that ANYONE should be able to see the difference between MF and high-end DSLR images (but I did say that I could in respect of a bit of my own work), nor did I say anything about seeing such differences from 30 feet away. That was the other Mark. Let us keep our Marks de-confused .
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So, where does that leave us? Are all, or even most of the people that buy medium format equipment fools, willing to spend their hard-earned money chasing a chimera, or simply looking to boost their egos regardless of cost? I don't think so, and it seems to me that anyone that does, simply hasn't taken the time to do a simple side-by-side comparison for themselves.
Frankly, there is no argument, only lack of knowledge and experience, or living in denial.
Michael,
Nobody discusses the value of MF nor of MFDB, the only point discussed here is the gap in DR. Taking a bit of distance, I am really wondering what triggered the resurgence of this whole DR discussion in March 2010.
In this context, I am looking forward to trying out the Pentax 645D when it is released, that should enable us to clearly separate the topics of vendors, price and format for the sake of a healthy discussion.
Cheers,
Bernard
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Thanks Fred, very interesting indeed. And for sure much more relevant than the assumed DR advantage of these magical backs.
Cheers,
Bernard
OT, but just to underline - that website is an excellent resource in general on MF-LF photography for those who read French. I just wish they would use larger font size and lighter background.
Mark
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Michael,
Nobody discusses the value of MF nor of MFDB, the only point discussed here is the gap in DR. Taking a bit of distance, I am really wondering what triggered the resurgence of this whole DR discussion in March 2010.
In this context, I am looking forward to trying out the Pentax 645D when it is released, that should enable us to clearly separate the topics of vendors, price and format for the sake of a healthy discussion.
Cheers,
Bernard
Bernard, I was really intrigued by your mention of this camera some posts further back. IF they really do release this product anywhere within a reasonable range of the price point you suggest, it COULD INDEED be a game changer depending on a number of factors of course, not the least of which would be the quality of Pentax service backing it up. The one experience I had with them here in Canada has soured me on anything to do with Pentax, much as I have always respected the high quality of their optics and the practical design and pricing of their equipment going back many decades. Anyhow, on the technical side, if and when it does hit the market, it will deserve, and of course get, a very serious looking over in terms of value for money. Depending on the outcome of those analyses, it could either change games or it won't. No point speculating now - all that remains to be eagerly anticipated. There's nothing like competition and brand-agnosticism to keep life interesting for us consumers.
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Absolutely correct. That would be exactly what is needed. However, Stouffer tops out a just over 4 OD, and I'm now using an over 5 OD chart so as to fully ensure I'm not missing anything in the noise floor. So on a Stouffer, I shoot a bracket of exposures to ensure I can see the full range.
Graeme
As i understand neither Mark Dubovoy nor Michael claim the DXO results and other measurements are incorrect - the idea is that they are irrelevant from the photographers and printers perspective.
But since there is the claim of 13 vs. 7 stops of MFDB vs. DSLR it is reasonable to ask for the basis of these numbers. Mark Dubovoy says the 7 stops are based on the 'universal consensus' of DSLR makers when comparing to film. The 13 stops are from sensor specs.
IMO it is safe to assume the 13 stops refer to the engineering definition of DR and considering this could be lower under practical circumstances (sensor built into a back and used in non-lab conditions) the DXO measurements are close enough to support this. That leaves us with the 7 stops claim - a value which since given in context with film DR could well refer to a kind of 'practically usable DR' kind of understanding of DR as it has been mentioned in this thread. So if we assume (just wildly guessing here) that this definition difference makes up for 2 stops and that Mark Dubovoy's poll was made some time ago when DSLR capabilities were still about 2 stops lower in DR than today we are already much closer to the DXO results.
Greeings,
Christoph
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"Anecdotal Evidence" is no evidence at all.
Whether we want to agree with it or not, "Relative Log Exposure" is a fixed way of measuring a capture medium's (film or digital) ability to respond to different levels of light. In otherwords, dynamic range. The following information is from the published datasheets for the listed films.
In the case of Fujichrome Velvia 100 (RVP 100), the straight-line section is just over four stops, with a couple stops either way in the toe and shoulder.
In the case of Fujicolor Pro 160S, the Relative Log Exposure shows about 9 stops--depending on how you interpret the curves.
In the case of Ilford Delta 3200, there really is no straight-line section, but the Relative Log Exposure range is around 12 stops.
What DXO attempts to do is shot Relative Log Exposure curves for digital cameras. Doesn't anybody else find it interesting that not only do the manufacturers of digital cameras NOT give us published specifications of the sensors, but we photographers aren't demanding them? Shame on us. If the camera companies insist on being the new "film manufacturers", then we must demand the same information from them that we got from the real film companies.
Frankly, I get pretty bored about the subject of dynamic range and digital sensors. Arguments over that are frequently the signs of little minds at work. While we argue over dynamic range, and resolution, we ignore issues like color accuracy and fidelity as well as the ability to capture certain colors like lavender and violet.
Michael, I know you and your friends are "top industry experts" but you've got to do better than this. I don't care how many credentials you guys have--you can't dumb stuff down to "Ken Rockwell" like claims. We expect more from you. We already have one Ken Rockwell and he's just fine at what he does. We just don't want you to copy him.
And PLEASE, it's "lose" not "loose".
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Hi,
Something I noted that when the Swedish periodicals write something about successful photographers they almost invariably use a digital Hasselblad, among other stuff. I don't know if that's because they need DR, Megapixels or what. Probably many reasons.
Being an engineer by training I have a strong preference for things that can be explained by common sense and physics. The DR advantage MFDBs are stated to have is not obvious to me from that standpoint.
I guess that Sweden is a Hasselblad country, it was invented here...
Best regards
Erik
I'm not going to fan the flames any more than needed, but I can't resist making one more comment in support of Fred's.
The world-wide market for medium format backs is approximately 7-8,000 units. That's all manufacturers combined.
These devices (with camera body and a couple of lenses) are priced in the $30–$50,000 range U.S. As Mark pointed out in his essay, that's the cost of a current luxury car.
One more factoid: About 70% of MF systems are bought by working professional photographers, the rest by fine art photographers and wealthy amateurs.
Here's the point. For the pros an MF system is a tool for earning their livelihood. It is purchased with the intention of helping them make money. No person would spend a good chunk of a year's income on a tool that did not offer an advantage. In my experience every pro that I know (and I know quite a few around the world) has done their own exhaustive comparisons and test, not relying on web site chatter, magazine reviews and online tests.
The fine art photographers are in a similar boat. They too make their livelihood (or a good part of it) from exhibiting and selling their prints. If a $1,000 to $6,000 DLSR gave them what they needed, why on earth would spend $30-$40,000 on a back?
As for the wealthy amateurs, I'll just say that it my experience (having taught and worked with several thousand folks like this over the years on my workshops and tours) I have yet to meet one who wasn't a savvy business person who understands the value of a dollar. Like the pros and the fine art guys, they spend that kind of money for an MF back because they believe that it will provide them with a tool that allows them to produce superior quality images. And if you speak to the people at major VARs who sell this gear, you'll learn that the amateurs are often even more demanding as customers than pros.
So, where does that leave us? Are all, or even most of the people that buy medium format equipment fools, willing to spend their hard-earned money chasing a chimera, or simply looking to boost their egos regardless of cost? I don't think so, and it seems to me that anyone that does, simply hasn't taken the time to do a simple side-by-side comparison for themselves.
Frankly, there is no argument, only lack of knowledge and experience, or living in denial.
Michael
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As i understand neither Mark Dubovoy nor Michael claim the DXO results and other measurements are incorrect - the idea is that they are irrelevant from the photographers and printers perspective.
But since there is the claim of 13 vs. 7 stops of MFDB vs. DSLR it is reasonable to ask for the basis of these numbers. Mark Dubovoy says the 7 stops are based on the 'universal consensus' of DSLR makers when comparing to film. The 13 stops are from sensor specs.
IMO it is safe to assume the 13 stops refer to the engineering definition of DR and considering this could be lower under practical circumstances (sensor built into a back and used in non-lab conditions) the DXO measurements are close enough to support this. That leaves us with the 7 stops claim - a value which since given in context with film DR could well refer to a kind of 'practically usable DR' kind of understanding of DR as it has been mentioned in this thread. So if we assume (just wildly guessing here) that this definition difference makes up for 2 stops and that Mark Dubovoy's poll was made some time ago when DSLR capabilities were still about 2 stops lower in DR than today we are already much closer to the DXO results.
Greeings,
Christoph
Sensor spec for DR would be full well / read noise, which is not what DXO do - they point a real camera system at a target and measure the resulting image. Yes, it does give a measure of "engineering" DR, but it's objective and repeatable. Practical DR is = Engineering DR - personal noise tolerance. Given many will measure engineering DR very similar, but personal noise tolerance differs wildly upon people, use of photo and scene, the only reasonable number to report is the engineering one and let the individual subtract their number based on their experience.
Graeme
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I have a bad cold this morning so useful work is out of the question. Mark D’s mention in the article of being able to tell the difference between Medium Format dynamic range and DSLR range at 30’ caught my attention. Now, I don’t have a medium format back but I do have a gorgeous print of one of Michael Reichmann’s pictures that, as I recall, he took with a medium format back. I don’t have a new DSLR either but I thought I’d make it even easier to see the difference if I used a print from a Nikon 990 from 10 or so years ago. That should be really obvious shouldn’t it?
My experimental methodology is rather rough (not having much energy): the pictures are different sizes, the subject is different, one has UV glass the other doesn’t, there’s a light fog this morning, this picture is just taken with the paltry range of a Canon G10, and my attempts at holding the camera steady were lackluster because I kept having these occasional shaking fits. The one thing for sure is that you are looking at the two pictures from about 30 feet away.
The other thing I’m sure about is that the photo on the right is of a duck.
Dave
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This has probably been pointed out already, but specifications for chip family packages are readily available. I suspect one could also get specs for the custom variants. For eg. Dalsa:
http://www.dalsa.com/sensors/products/sens...Number=FTF6080C (http://www.dalsa.com/sensors/products/sensordetails.aspx?partNumber=FTF6080C)
On the whole, an interesting balance of compromises that yields a surprising DR given the very fast readout, high temperatures and low cost. To put it in context, a scientific grade CCD can easily exceed $30K on its own and the support package is more than that.
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So, where does that leave us? Are all, or even most of the people that buy medium format equipment fools, willing to spend their hard-earned money chasing a chimera, or simply looking to boost their egos regardless of cost? I don't think so, and it seems to me that anyone that does, simply hasn't taken the time to do a simple side-by-side comparison for themselves.
Frankly, there is no argument, only lack of knowledge and experience, or living in denial.
Cynnical translation: you know what you know, facts and explanations from the hoi polloi be damned.
You might have a valid point with this post, if you were responding to yet another "35mm DSLR is just as good as MFD" thread, but that is not the case here. This thread was started specifically about the unsubstantiated claim that MFD has a 6-stop advantage in DR over 35mm digital, which you repeated and agreed with in your Editor's Note.
I have to agree with image66, this site's editorial content has lost credibility on technical matters of late...
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I have absolutely no doubt that you are completely correct: the medium format backs justify their premium price.
Now, having got that out of the way and returning the the question of this 6 stop advantage over 35mm sensors....
Frankly, on the face of it that sounds absurd. If the claim had been that there was a 1 stop or perhaps 2 stop advantage I might believe it without cast iron evidence as it sounds plausible given what we have seen with the short life of digital. But 6 stops would represent something like the largest difference in a critical measured parameter of imaging technology there has ever been. It's a ridiculous chasm in capability! Think about the huge amount of work fuji had to do, inventing a completely new way of doing things to get an extra 2 stops. I don't think any more discussion is worthwhile without some hard evidence. To quote Richard Dawkins (on his own forum, interupting a debate) "I don't care what your opinion is, it's worthless; I don't care what my opinion is, it's worthless, too. Show me the evidence. " In this case the purported difference is so huge that even the often invoked blind man ought to be able to judge it in about 1/10th sec...
regards
Dave
I'm not going to fan the flames any more than needed, but I can't resist making one more comment in support of Fred's.
The world-wide market for medium format backs is approximately 7-8,000 units. That's all manufacturers combined.
These devices (with camera body and a couple of lenses) are priced in the $30–$50,000 range U.S. As Mark pointed out in his essay, that's the cost of a current luxury car.
One more factoid: About 70% of MF systems are bought by working professional photographers, the rest by fine art photographers and wealthy amateurs.
Here's the point. For the pros an MF system is a tool for earning their livelihood. It is purchased with the intention of helping them make money. No person would spend a good chunk of a year's income on a tool that did not offer an advantage. In my experience every pro that I know (and I know quite a few around the world) has done their own exhaustive comparisons and test, not relying on web site chatter, magazine reviews and online tests.
The fine art photographers are in a similar boat. They too make their livelihood (or a good part of it) from exhibiting and selling their prints. If a $1,000 to $6,000 DLSR gave them what they needed, why on earth would spend $30-$40,000 on a back?
As for the wealthy amateurs, I'll just say that it my experience (having taught and worked with several thousand folks like this over the years on my workshops and tours) I have yet to meet one who wasn't a savvy business person who understands the value of a dollar. Like the pros and the fine art guys, they spend that kind of money for an MF back because they believe that it will provide them with a tool that allows them to produce superior quality images. And if you speak to the people at major VARs who sell this gear, you'll learn that the amateurs are often even more demanding as customers than pros.
So, where does that leave us? Are all, or even most of the people that buy medium format equipment fools, willing to spend their hard-earned money chasing a chimera, or simply looking to boost their egos regardless of cost? I don't think so, and it seems to me that anyone that does, simply hasn't taken the time to do a simple side-by-side comparison for themselves.
Frankly, there is no argument, only lack of knowledge and experience, or living in denial.
Michael
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Hi jeff,
Well I do not think LU-LA has lost credibility, maybe at the contrary.
Again, I have to agree with Michael's post about ambiguity. I do not agree for agreeing, if I did not I would say it clearly, so let me explains my thoughts.
When I hear talking about scientific rigor (that rigor that was supposed to missed here in that topic), as if science was able to put a definitive and absolute answer with graphics, and when I turn towards real scientits like Ed Witten, these guys always talk about the ambiguous part of laws and nature as a full component of the ecuation. Ambiguity is part of reality and the 5 o 6 stops may be true in some cases, in other case not. But if it CAN be true in some cases, then it is not a wrong information.
About this famous comparaison with the G10, of course that it is true...BUT, now...lets take the G10 file in severe post production like in fashion, art or advertising. Everybody would agree that there is no room for that. The file simply does not contain enough information to handle such a treatment, and that kind of treatment is the standar in professional photography. (without talking about the enlargement of course). So, yes, Michael is right. He is just saying that "you can do that with the G10 file", but he was not saying "both files had the same capacities". So it became a kind of ambiguous argument, some have seen contradictions but in my understanding there was absolutely no contradiction.
About the display on the web, I put a post in the past talking about that, but I did not know that it was such a sensitive topic. Well, yes, it is possible to see the differences in low resolution on the web. It is not scientific but perceptual. I do see it and for sure many of you.
One day, a member send a link in a topic about LF, a site with contact prints. You can tell the difference right on the web. There is something very special, an overall sensation of quality and clean that simply does not exists with smaller sensors. And one of the sensation resides between the transitions in the tones.
I can see it on the web, why not on a print so?
MF users are talking about the differences they see between the back brands. For example Leaf has a fame to be closer to film etc...it seems that in MF users, there is a general consensus about these differences that are clearly visible. What Mark post about the Hasselblad style ( for reproduction etc...) is known and visible. Would it be measurable? Maybe not.
Also, many of the MF detractors would die to have an MFD to work with. This is a major contradiction, much more than the G10 one don't you think?. The only one who post clearly a coherence about that, was Bernard when he said he would not buy an MF back even if they were cheaper than Dslr. But many of us would love to have one and work daily with it. Is it not true?
Sorry gentlemen, I respect your views and opinions but I still trust Michael, even more after his last post about ambiguity.
Now I'm going away from the flames because it is hot hot
Best regards,
Fred.
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2 facts.
1. In most websites you can read that S90 has a better dynamic range (about 1 f-stop) than the G10.
After a lot of tests I can say that at ISO80, for RAW files developped with LR2.6, the G10 is better in terms of dynamic range and color accuracy !
At ISO200 they are equals, and above S90 is better.
It is strange, because I cannot give any scientific explanation for that fact !
But it's like that.
2. Up to 8-9 f-stop it is easy to show differences in terms of dynamic range and color accuracy.
Above, it's often very difficult for a lot of reasons: very limited DR of paper, shadows areas purity, color shift in very bright zones,...
So we need a more rigorous definition of dynamic range, and a use of the same protocol.
Another strange thing, I've re-discovered old scanned film photos saved in jpeg.
I was able to recover far more highlights than with my Fuji pocket camera jpegs.
So yes, it's possible that MF have a 2 or 3 f-stop advantage, but 7 seems unbelievable.
Have a Nice Day !
Thierry
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What Mark post about the Hasselblad style ( for reproduction etc...) is known and visible
unlikely. It rather shows that he couldn't even manage to run the software correctly: http://luminous-landscape.com/forum/index....st&p=351480 (http://luminous-landscape.com/forum/index.php?s=&showtopic=42078&view=findpost&p=351480)
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Sorry gentlemen, I respect your views and opinions but I still trust Michael, even more after his last post about ambiguity.
Sorry, Fred ... but not one thing you've said has been on point in this entire thread.
It ain't about trusting anyone ... it's about backing down from a preposterous claim everyone knows is completely nonsensical.
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Jack - let me correct this - there are two Mark's active in this discussion - the writer of the article who is Mark Dubovoy with a PhD, and then a member of the discussion audience - me - Mark Segal, who does not sport a PhD. I did not make any statement to the effect that ANYONE should be able to see the difference between MF and high-end DSLR images (but I did say that I could in respect of a bit of my own work), nor did I say anything about seeing such differences from 30 feet away. That was the other Mark. Let us keep our Marks de-confused .
My apologies good sir!
I was having enough trouble discussing Mike and Michael on the thread below this one, that dealing with Mark and Mark got me turned around on this one
I will enter an edit correction immediately
Jack
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Well I do not think LU-LA has lost credibility, maybe at the contrary.
...
As has been repeated ad nauseum, the main point of contention is the claim of massive difference in dSLR and MFDB dynamic range. I and apparently some others believe this is due to comparing apples to oranges which yields invalid results. Most likely this is empirical tests for dSLRs vs. published manufacturer figures for MFDBs.
This even when there is a perfectly adequate objective source of data in DXOmark. While one can argue about the validity of their data, they do have a consistent and published methodology. Therefore comparing their figures between dSLRs and MFDBs would show if there was such a massive difference in DR, although the absolute numbers might be different than what the "real-world" DR is.
Nevertheless, the author of the article nor Michael have been forthcoming with any data to support the claim. I've only seen peripheral anecdotes, "expert" "consensus" unsupported by evidence, and plenty of smoke and mirrors. This certainly doesn't fair well for credibility.
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Sorry, Fred ... but not one thing you've said has been on point in this entire thread.
It ain't about trusting anyone ... it's about backing down from a preposterous claim everyone knows is completely nonsensical.
Correct Jeremy. Some of the things I said yes indirectly have something to do.
But I got your point and agree, specialy about the use of language. Trusting was not the correct word.
Well, when I wrote "trusting" I mean that I think Michael is right about DR.
Now as someone said we would need a standar because it seems that it is not that clear at all.
Regards,
Fred.
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Nevertheless, the author of the article nor Michael have been forthcoming with any data to support the claim. I've only seen peripheral anecdotes, "expert" "consensus" unsupported by evidence, and plenty of smoke and mirrors. This certainly doesn't fair well for credibility.
WMD in Iraq... and LuLa like Fox News w/ Michael being O'Reilly then.
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unlikely. It rather shows that he couldn't even manage to run the software correctly: http://luminous-landscape.com/forum/index....st&p=351480 (http://luminous-landscape.com/forum/index.php?s=&showtopic=42078&view=findpost&p=351480)
Aaaaarrrggg...
But Hasselblad is known in the world for that. Museums, intitutions etc...Maybe Mark did it not so bad with the software.
You convinced me, and I'm going to study these fantastic japanese paper with Bernard.
I will never enter any more on a technical topic about 35mm and MFD. Too hot without fireman jacket.
Cheers to all, and sorry for my sometimes clumsy english. Hope I was not too much.
Fred.
edit: Maybe what I tried to manifest is that point in form of a question: Michael Reichmann or Mark Dubovoy are not specialy known for their lack of rigor and knowledge in the photography community, right? So, why would Mark put a completely non-sense information on a web that is visited worldwide? Then, Michael would have post an editor's note rectifying this point, don't you think? But he confirmed more or less Mark's information. My question is why? They might have good enough reasons for that I guess. Knowing that Michael uses daily MFD as 35mm, why would he put a completely false information? That does not make sense. I think this question is not that silly and maybe before these bombing of criticisms we might also think that they maybe right. That was my point.
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But Hasselblad is known in the world for that. Museums, intitutions etc...Maybe Mark did it not so bad with the software.
known for a contrasty oversaturated look by default? Not that I know of ...
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John,
There is nothing dishonest going on; and yes, I stand behind both positions.
How is this possible? Simple. Many things in life are ambiguous, and a tiny change in beginning state can lead to a huge difference in end state.
It was Fitzgerald who wrote, "Intelligence is the ability to hold two opposing ideas in mind at the same time and still retain the ability to function."
Very philosophical of you Michael
I understand the gist of what you're saying. However, it's the word "tiny change" that I have trouble with. If in one article you hold that trained professionals can't see a difference up close with 11x17 prints from a G10 and a P65 ... then, to me, another article stating that any knowledgeable person should be able to see the difference in a print from a P65 and a top DSLR from 30' away is more than just a "tiny" difference, it is an otherworldly difference.
In the case of the G10 vs Phase article most of the "trained observers" couldn't see the difference in 11X17" sized prints between the two cameras. But, of note is that there were a few who could. How? Because they didn't look at sharpness alone. They looked at depth of field, tonal accuracy, dynamic range and several other characteristics (including some that are hard to name) that gave the game away. Even pros can be mislead.
Well, again, only "a few" being able to see the differences up close between a G10 and a P65 on a 17" image somehow doesn't wash with the implication that ANY knowledgeable person should be able to see the difference between a "small" print from a P65 and a top DSLR from 30' away.
So, I am not so sure it's a matter of even the pros can be mislead as it is a matter of even well-meaning authors can be misleading ...
There has been more than one person comment that they can tell just by looking at my Home Page shots which have been taken with MF and which with other cameras. In an 800 pixel image this simply shouldn't be the case. But it is easily the case for those with a good eye.
I do agree (and myself can see) the difference in quality in a MF image and a P&S image, at only 800 pixels width, staring me square in the face on my 26" monitor. So maybe I too have a good eye.
However, this is a far cry from being able to see the difference in a small P65 image and a top DSLR image from 30' away. This isn't having "a good eye," it is having super-human eyes that don't exist.
Thus I think the problem isn't in the concept, the problem is in the exaggeration in describing the concept.
I could go on, but won't. In the end what I've seen over the years (decades) of doing and teaching photography is that nailing down the question of image quality is a slippery fish. Just when you think you've got a grip, it pops out of your hands.
I guess that I'll simply continue my life knowing that photography, as with life itself, is full of contradictions.
Michael
You are correct that life is full of contradictions. The trouble is, some contradictions are "paradoxical truths" that philosophers have pondered throughout the ages, while other contradictions are blatant double-talk involving impossibilities.
Again, I don't think anyone here has a problem with the concept that there are subtle tonal/IQ differences that (in LARGE images) can clearly be seen in MF images versus DSLR images ... the problem is in the exaggeration that these differences are so profound that they can be seen from 30' away ... while on the same site there is another article stating that even a G10 could fool most pros up close on even larger images.
I think both articles contained exaggerations, first one way, then another.
Anyway, I think the tendency to subjectively exaggerate is what has caused the uproar, rather than just dealing with measurable facts. Again, I am not trying to be rude, and I know we all can tend to exaggerate, but sometimes it can come back to haunt us if we do so to people who are looking for the exact truth, and not somebody's "impression" ... that may or may not hold true if he gets up on the other side of the bed the next day.
Jack
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My 2 cents:
When you use the best processing software for each, and take into consideration tonal gradation, absolute detail, and color fidelity of the shadows and highlights I consistently find the modern Phase One and Leaf backs to exceed the dynamic range of any dSLR I've used (mostly Canons since we are a Canon dealer). However, 6 stops does exceed my personal experience. I won't even bother to quantify it other than to say it is, in my opinion, significant. When pushing around a file from, e.g. a P65+ I'm consistently blown away by just how far it can be pushed or pulled while keeping smooth tones, realistic, color accurate, noise free, and detailed content.
In other words there is a huge difference between engineering "detail" (meaning the ability to discern a signal over noise) and photographic detail suitable for printing or commercial use. If I can recover "detail" in a dSLR file but the color is muddy, the noise is ugly, and the tones are jaggy, blotchy, or otherwise not smooth and natural then that, in my opinion, does not count as usable DR.
The most important thing to me is that in difficult real world scenes (e.g. a contrasty landscape) the difference of even 1 stop of DR is the difference between holding detail in the highlights and shadows or having detail-less clouds with muddy shadows. If the scene requires X and you have X-1 only multiple exposures can save you.
Doesn't take much time shooting skin tone in sunlight with dark fabric to see the difference. The first thing to go is the smoothness and color accuracy of the skin as the red channel starts to clip.
Doug Peterson ()
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I am not trained as a photographer but as an engineer. I don’t have years of photographic experience and barely do enough commercial work to be able to get by, the rest of the time I shoot my passion. I invested in Nikon glass and bodies, invested in Epson and learned what makes my eyes happy. I fell into Contax645 and Phase One by chance and even though all my gear is old the difference in the dslr & mfdb are obvious. You can see on my studio walls in the proof prints the difference in the sensor systems.
I don’t have an ax to grind or am married to any position or product except my Epson 9880. As I look around my studio one can see in the prints the difference between the systems. The proof I have always felt was in the print. Right now that is what drives my view of the MFDB, that final print. To that end I have invested in lighting and moving my skills in MF directions learning how to use this tool in the environments where I previously used Nikon. And learn I have had to do, all my bad habits have come back to haunt me forcing me to be far more me meticulous in my approach.
I cannot explain in literal terms why the frames are so different. In working with repro of oil/acrylics the artists like the MFDB files better than the previous system. Portraiture is the same, MFDB consistently produces a better file. Chasing the magic hour takes a five frame stitch to capture the same tonality of a single frame of the mf.
I am willing to accept the downside of MF simply because of the final print. The clarity and dynamic range of the mf clearly is better than anything I produced with Nikon, single frame, panorama or HDR. Can I live without my Nikon? Not a chance, but I will always be pushing to find a way to use the Phase One back where ever I can simply because it produces the best print which for me as a photographer and individual is why I shoot.
Mark’s review confirmed my view of the open system of Phase One and helped me decide that the next chunk of silicon I will purchase will be a Phase One back to run on my Contax645. In the end it is the intangible of what my eyes like no matter how often I go look at the DXO labs page which seems to tell me different.
Mark Prins
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When pushing around a file from, e.g. a P65+ I'm consistently blown away by just how far it can be pushed or pulled
that will be just +/- 2.5 stops in CaptureOne, right ?
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My apologies good sir!
I was having enough trouble discussing Mike and Michael on the thread below this one, that dealing with Mark and Mark got me turned around on this one
I will enter an edit correction immediately
Jack
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Thanks Jack - and yes, it can all get confusing indeed!
Mark (S, non-PhD)
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that will be just +/- 2.5 stops in CaptureOne, right ?
If the sensor has good shadow noise, pushing of 2.5 stops is entirely reasonable, but if you can recover 2.5 stops of highlight detail, then you are not exposing to the right.
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When you use the best processing software for each, and take into consideration tonal gradation, absolute detail, and color fidelity of the shadows and highlights I consistently find the modern Phase One and Leaf backs to exceed the dynamic range of any dSLR I've used (mostly Canons since we are a Canon dealer). However, 6 stops does exceed my personal experience. I won't even bother to quantify it other than to say it is, in my opinion, significant. When pushing around a file from, e.g. a P65+ I'm consistently blown away by just how far it can be pushed or pulled while keeping smooth tones, realistic, color accurate, noise free, and detailed content.
There you go.
Cheers,
Bernard
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I don't see why the G10/MF and DSLR/MF statements are incompatible. You shoot a low contrast, high-DOF scene: nothing to differentiate a G10 from MF in a relatively small print, since it's within DR and max resolution of both. You shoot a high contrast scene: the system with larger DR produces a print that is dramatically different from the system with lower DR.
When the authors wrote "6 f-stops", I assume they should have written "considerably more", which is what they probably meant. Because I don't know how any working photographer (as opposed to an imaging scientist with measurement tools) no matter how technically competent he is, can evaluate the difference to be "6 f-stops", as opposed to "5 f-stops", or "4 f-stops", and it's easy to slip from there. I certainly can't - although in some occasion I have able to expose transparency film correctly without a meter. But I'd recognize "considerably more" DR if I saw it.
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Bernard, I was really intrigued by your mention of this camera some posts further back. IF they really do release this product anywhere within a reasonable range of the price point you suggest, it COULD INDEED be a game changer depending on a number of factors of course, not the least of which would be the quality of Pentax service backing it up. The one experience I had with them here in Canada has soured me on anything to do with Pentax, much as I have always respected the high quality of their optics and the practical design and pricing of their equipment going back many decades. Anyhow, on the technical side, if and when it does hit the market, it will deserve, and of course get, a very serious looking over in terms of value for money. Depending on the outcome of those analyses, it could either change games or it won't. No point speculating now - all that remains to be eagerly anticipated. There's nothing like competition and brand-agnosticism to keep life interesting for us consumers.
Well, I find this camera hugely interesting, because it will be the first digital camera ever released by a company with both experience in MF and digital technologies.
Mamiya was in essence a company with MF experience but none in digital. Nonetheless, the ZD was an interesting offering and got a good review from Michael who was then especially impressed by its DR. By the way, the same DR that, as a Mamiya ZD user, I now believe is clearly inferior to that of my D3x. I know why he was impressed and why I am not, but I will not re-open this debate here.
I believe that the Pentax has the potential to be a much better device at a price point that will be below 10.000 US$ for sure. It will because:
- Few people will pay more for a camera in Japan,
- They need to establish their credibility,
- Pentax knows economies of scales better than anybody else in the camera industry,
- They tend to be objective about the respective value of their technology vs others. The benchmarks done by Nippon Camera and Asahi camera are based on real tests, not on opinions. As a result, they will price their MF camera in a way reflecting the actual gap relative to this generation of high end DSLRs and the next one to be released a few months from now. This makes prices above 10.000 US$ un-realistic.
If this works out per the plan, Pentax might end up saving the industry by giving the maker of the chip they use the opportunity to produce significant volumes and therefore catch up in R&D investments relative to the Japanese chip designers. I believe that they will also put price pressure on the other guys in the industry which is someone we should all be happy about, unless we work for one of them of course.
Cheers,
Bernard
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I don't see why the G10/MF and DSLR/MF statements are incompatible. You shoot a low contrast, high-DOF scene: nothing to differentiate a G10 from MF in a relatively small print, since it's with DR and resolution of both. You shoot a high contrast scene: the system with larger DR produces a print that is dramatically different from the system with lower DR.
True,
In the case of the G10 vs back though another phenomenon was playing. The scene chosen had so much DR that both devices were unable to capture it, or put it otherwise, the exposure of both devices was chosen so as to favor shadows (tree trunks).
The problem many people had with that piece is that Michael didn't focus his essay on explaining why it was possible to pick a scene showing very different devices as being similar, but he just focused on the end result. The takeaway from many folks around (including some friends) was a huge boost in their impression about the abilities of the G10.
Cheers,
Bernard
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(http://i33.photobucket.com/albums/d51/msmambo/WRONG.png)
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about DR ...
It's like measuring a car's horsepower, but DXO measures how much the engine can make on an engine stand while the number that matters to drivers is how much gets to the road. Both measurements are technically correct, but one matters more when it comes to getting work done and it isn't the DXO number believe me. Software packages like Imatest make this clear and report several figures for DR using different thresholds. DSLR's come out on top with engine stand / test lab type numbers but really fall down on the how much power hits the road types of tests. Not un-commen for those numbers to drop to 70% or even down to half but MFDB don't change all that much.
So in the end - you both are right, but you're not talking about the same measurement.
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about DR ...
It's like measuring a car's horsepower, but DXO measures how much the engine can make on an engine stand while the number that matters to drivers is how much gets to the road. Both measurements are technically correct, but one matters more when it comes to getting work done and it isn't the DXO number believe me. Software packages like Imatest make this clear and report several figures for DR using different thresholds. DSLR's come out on top with engine stand / test lab type numbers but really fall down on the how much power hits the road types of tests. Not un-commen for those numbers to drop to 70% or even down to half but MFDB don't change all that much.
So in the end - you both are right, but you're not talking about the same measurement.
If the road is the print how can you have 6 stops of difference in a print?
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about DR ...
It's like measuring a car's horsepower, but DXO measures how much the engine can make on an engine stand while the number that matters to drivers is how much gets to the road. Both measurements are technically correct, but one matters more when it comes to getting work done and it isn't the DXO number believe me. Software packages like Imatest make this clear and report several figures for DR using different thresholds. DSLR's come out on top with engine stand / test lab type numbers but really fall down on the how much power hits the road types of tests. Not un-commen for those numbers to drop to 70% or even down to half but MFDB don't change all that much.
So in the end - you both are right, but you're not talking about the same measurement.
That would be fine if we were talking about 1, 2 or maybe even 3 stops. But the claim made is 6 stops of difference in DR. To put this into digital perspective, it's akin to comparing a 7-bit image (128 colors) with a monochrome 1-bit image.
Another perspective is that DXO puts 10D and 1D MkIV at only 1 stop apart in DR - and the latter was released almost seven years after the former - so we'd have to compare some mid-90s digital cameras to get to a 6-stop difference.
I wouldn't be surprised if MFDBs do offer higher real-world DR than dSLRs - although all I've seen are "I know better" claims. But putting the gap at 6 stops is akin to saying with a straight face that an Amish horse buggy has similar acceleration as a Bugatti Veyron (http://www.youtube.com/watch?v=ly48eFOH4nk) *
* if you're at all into cars and haven't seen the Top Gear Veyron clip: this is the be-all, end-all of car porn. You have been warned, you will never again look at cars the same way.
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Software packages like Imatest make this clear and report several figures for DR using different thresholds. DSLR's come out on top with engine stand / test lab type numbers but really fall down on the how much power hits the road types of tests. Not un-commen for those numbers to drop to 70% or even down to half but MFDB don't change all that much.
If this is true it should be easy to prove by publishing Imatest results to put this matter to rest. I'm not holding my breath, though...
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If this is true it should be easy to prove by publishing Imatest results to put this matter to rest. I'm not holding my breath, though...
Exactly...
Graeme
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(http://i33.photobucket.com/albums/d51/msmambo/WRONG.png)
Thank you ever so much for introducing this but of humour. Made my evening!
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so why bother to put the microlenses at all if they don't increase the amount of light hitting the light sensitive area... so albeit not ideally they still increase the amount of light reaching the needed place.
Certainly if you direct more light in, some of it will hit the light sensitive area.
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That would be fine if we were talking about 1, 2 or maybe even 3 stops. But the claim made is 6 stops of difference in DR. To put this into digital perspective, it's akin to comparing a 7-bit image (128 colors) with a monochrome 1-bit image.
Another perspective is that DXO puts 10D and 1D MkIV at only 1 stop apart in DR - and the latter was released almost seven years after the former - so we'd have to compare some mid-90s digital cameras to get to a 6-stop difference.
I wouldn't be surprised if MFDBs do offer higher real-world DR than dSLRs - although all I've seen are "I know better" claims. But putting the gap at 6 stops is akin to saying with a straight face that an Amish horse buggy has similar acceleration as a Bugatti Veyron (http://www.youtube.com/watch?v=ly48eFOH4nk) *
* if you're at all into cars and haven't seen the Top Gear Veyron clip: this is the be-all, end-all of car porn. You have been warned, you will never again look at cars the same way.
As I mentioned further above, it should be ABUNDANTLY CLEAR by now that what's going on here is a comparison of apples and oranges. The methods of measuring DR are differing between the 6-7 crew and the 13+ DxO crew, and this MUST BE driving the differences of outcome. If we're into car analogies, this discussion seems like measuring gas mileage where one camp says it's 8 and the other says it's 29.4, and the're both right except that the former is using L/100km and the latter MPG. Those who know both ways in which the DR measurements were likely made could help us a lot by drilling down to show HOW different methods produce such differences of numbers. I have a strong intuition that would collapse the perceived differences and put the matter to rest.
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By now its quite safe to bet the difference must be about useable and not about total DR.
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By now its quite safe to bet the difference must be about useable and not about total DR.
And why would about 5 or 6 stops of DR be "unuseable"?
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And why would about 5 or 6 stops of DR be "unuseable"?
Im was not implying specific numbers.
So far it has been made plausible that measureable DR of current 35mm and MFDB Sensors should be roughly the same. So a difference, if any, must be about useable DR, and this on the other hand has been made plausible too. Definitive proof is missing except for one D3-example. (Did I overlook something?) Exact values for a difference however are not yet clear, but very likely to be under 6 stops.
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Im was not implying specific numbers. Just what I said.
Sorry, but this is a bit facile. You're betting the "difference" is between total and useable. It so happens the so-called difference we're talking about in this thread is in the range of 6 to 7 stops. Therefore your statement implies specific numbers whether you meant to or not, and I'm wondering how such a huge amount can be "unuseable". I think it's a fair question.
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As I mentioned further above, it should be ABUNDANTLY CLEAR by now that what's going on here is a comparison of apples and oranges. The methods of measuring DR are differing between the 6-7 crew and the 13+ DxO crew, and this MUST BE driving the differences of outcome.
Yes, so the reasonnable thing to do would be to remove this claim from both the original article and editorial comment wouldn't it?
Cheers,
Bernard
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Yes, so the reasonnable thing to do would be to remove this claim from both the original article and editorial comment wouldn't it?
Cheers,
Bernard
Absolutely - if and when my hypothesis has been confirmed.
Cheers,
Mark
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Sorry, but this is a bit facile. You're betting the "difference" is between total and useable. It so happens the so-called difference we're talking about in this thread is in the range of 6 to 7 stops. Therefore your statement implies specific numbers whether you meant to or not, and I'm wondering how such a huge amount can be "unuseable". I think it's a fair question.
I agree it could be misunderstood. But I clarified it. I also edited my last post you cited.
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Yes, so the reasonnable thing to do would be to remove this claim from both the original article and editorial comment wouldn't it?
Cheers,
Bernard
I agree - And / Or, make available raw files P65+ / D3X / 1DSMK3 as demonstrable evidence of the claimed 6-7 stop advantage of MFDB. This would put the matter to rest one way or the other would it not?
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If this is true it should be easy to prove by publishing Imatest results to put this matter to rest. I'm not holding my breath, though...
I have done some of these tests and posted the results on this site in the past. I have only older digital backs so can't comment on the ones in question here but I would not be surprised if there were 3-4 stops difference between the current dslrs and newest digital backs in the measurment important to photographers, and virually no difference in DR in the kind of measurement DXO does. I don't think my imatest license is current so I won't be able to jump in and do them.
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Each time I come upon a post by Michael, I look for some hint of a claim with any sort of public standards for evaluating its veracity, any sort of common basis for determining its truth or falsity. But the only basis for claims offered is the Argument From Authority, appearing in different forms in differing postings.
Then I look at my D3S, with its linear mapped sensor, producing more than 12 good bits of data, at least 10 of which are clean by the strictest standards. With a linear gamma, this is ten plus stops of dynamic range. And I think, how do I interpret this when I'm merely offered the argument from authority as a counterargument?
Luke
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After reading through all the pages of discussion I think it boils down to the difference between medium format and 35mm. A 4x6 print from a medium format negative blows away a 4x6 print from a 35mm negative, even though the dynamic range (read film curve) is identical. Same goes for a projected slide; medium format blows away the 35mm. Yet the system resolution stays pretty much the same.
So it is not surprising that you see a difference between a medium format back and a 35mm DSLR. I am not sure it is dynamic range that makes the difference here. It is the same difference in tonalty and subtle colour range that makes the difference here.
Having learned to expose using transparency film, my experience is that my dslr has way more dynamic range than transparency film. The only real difference is that the velvia's black has a Dmax of 4 wheras the digital value of black is more or less 0plus sensor noise for that exposure.
As many have stated, we are dealing with apples and oranges here.
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Hi,
Following this discussion I see the ask these questions on the DR issue:
1) Is there any physically feasible explanation for MFDBs having more than two stops of DR? The area of the sensor is about 2.6 larger on the MFDB than on FX this should give a 1-2 step advantage, simple by collecting 2.6 times the photons.
2) If the MFDB has an advantage in DR over full size sensor why doesn't it work well at high ISO? If we assume exposing to the right, underexposure would be equivalent to increasing ISO. So 5 steps of underexposure on a 50 ISO would give 1600 ISO. Does a Phase One P65+ give better ISO 1600 performance than a Nikon 3DX? Does a lesser MFDB than the P65+ give ISO 1600 performance than a Canon 1DsIII. Reason for asking may be that according to the (in) famous DxO numbers both Phase and Nikon seem to have invented some magic sauce pushing the sensors additional two steps. Many readers may be tempted to buy used or simpler backs. Do they have the same magical DR?
3) How much of the perceived difference is not related to sensor but to lens flare? Have MF lenses fewer glass to air surfaces, better coating and internal shielding?
4) Do Phocus and Capture One utilize additional information from the sensor? If we use the MFDB with LR or ACR would we still see the same benefits?
What I'm looking for is a logical explanation on how the large difference in DR would arise.
The comparison by Mark Dubovoy was good read, a great thanks for sharing experience.
Best regards
Erik
Mark Dubovoy has done an outstanding, pretty much unbiased test, which is pretty interesting.
And then he writes:
"The dynamic range of a typical high-end professional 35 mm DSLR is around 7 F/stops. Medium Format cameras are closer to 13 F/stops of dynamic range. You can see the difference from 30 feet away in a small print"
You can see the difference from 30 feet! well.....
I'm a phase one user. A professional photographer, who uses the phase one (P 45) for 99% of my work. I also use a canon 5D when light is bad and I'm shooting people, and I want to use the ambient light. I will bet everything I own, and everything my wife owns, that no person on this earth could tell the difference between a small print taken with a high end dslr and a high end medium format digital back from 30 feet (10metres) away.
Any takers?
Stefan Siba
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Hey Johnathan, heres the original poster - Stefan.
I didn't percieve this thread to go down the comparing medium format versus dslr. That wasn't my original post.
I am a professonal photographer shooting thousands of phase one digital files a month.
I have done so for the last three years or more. I can also tell my MFDB photos from my DSLR photos. After all I shot them.
I hardly ever give any thought to DR. I know my phase one files are beautiful compared to what I was used to before I started using the back.
You say your 6x4 MFDB prints blow away your 6x4 DSLR prints. Well, that's not the point of this argument/discussion
So, if no one minds I'd like to reiterate what my initial point was.
I'll shout it:
IT IS THE 30 FEET away issue that I have. As several posters have thankfully also picked up on, 30 feet is a bloody long way away to see any difference in two prints. Let alone two prints of the same subject taken by the same photographer under the same conditions, processed the same way and printed with the same care.
I am a MFDB user and yet find it surprising that anyone would endorse a comment that claims that from 30 feet away one can tell that a SMALL PRINT was taken using a MDFB
I especially like the duck example. Thank you Dafu post 127
I'm fairly sceptical of the 6 to 7 DR difference, but we can just go round in circles getting smuggish I know better answers from a few people and start going round again. Let it be 6, 7, or call it DR or lenses, or Miriam for that matter. If you guys don't mind I'd like to steer this converastion more towards seeing a print at a certain distance and being able to tell that it is MFDB as opposed to DSLR.
cheers all.
Stefan
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Reading Michael's editorial note at the end of the about f-stops of dynamic range, the question that comes to my mind is - will it always be this way?
Is there something intrinsic to how MF digital backs are made that causes them to have better dynamic range?
If it is simply size, then why haven't we seen a decline in dynamic range as photosites have shrunk in DLSRs?
If this is a result of sensor technology improving, then shouldn't it be possible for Canon/Nikon/Sony to churn out a DSLR with large photosites and thus higher dynamic range?
Or perhaps one might ask, why hasn't Nikon been able to reach a higher dynamic range with their lower MP count modern DSLRs?
If it isn't photosite site, is this the difference between CMOS and CCD?
Or is it something else?
I clicked on through to the cambridge colour link and whilst they discussed what dynamic range was and how it affects pixels, they didn't try to explain why the numbers are what they are.
I'm not yet ready to accept that because the camera is 35mm must mean that it has half the dynamic range of a bigger camera. There's got to be a cause...
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OK, so now that I think about it, there is also the DR subplot which is at the start of the incriminating sentence from Mark Dubovoy (not Mark Segal ); which is difficult to dismiss.
The point of Mark Dubovoy's remark was that there is such a HUGE difference between MFDB and DSLR, and that it is the DR that makes this difference tangible, as it were.
But, let's not get too caught up with the DR.
Please let us first refute the notion that one can tell what format camera was used, when looking at a 10x8 print from 30 feet away.
Once we do this I'll be able to sleep at ease, and let anyone who wants to do so, talk about the exact difference between DR of MFDBs and DSLRs to their heart's content.
cheers again
Stefan
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The reason I don't want to get caught up in the exact DR difference between a P65+ and a highest end DSLR, is that there may well conceivably be, in some way, a 6 or 7 stop difference.
I can't predict where the proof may come from. I can't imagine where it may come from. But it may be out there. Who knows? Stranger things have happened.
What I am absolutely certain of is that from 30 feet (10 metres), you can not tell with any certainty whether a 10x8 print was taken with a MFDB or a DSLR. And I would claim that given most normal circumstances, you probably wouldn't be able to tell the difference between the same scene taken with a MFDB and an iphone. My iphone would by definition have close to no DR, so the difference would be the whole 13 stops.
I was drinking Sangre de torro 2003 reserva, now I'm on the yellow tail merlot.
goodnight all
Stefan
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Hi,
A larger sensor collects more photons and can also store more free electrons. A MFDB sensor (with 1.0 crop factor) has a surface area 2.6 times that of an FX (crop factor 1.0) DSLR sensor. All other aspects kept constant this should increase DR by about one stop.
Usable DR may be more limited by "photon shot noise", random variations of collected photons, than by readout electronics. The engineering definition of DR is log2(Maximum Signal/Signal at SNR==1).
I cannot see any reason (on the sensor side) that an MFDB would have any advantage regarding DR in excess of one stop over an "FX" sensor. This applies to both "engineering DR" and "usable DR". I'm not saying that the advantage does not exist, I'm just saying that I have not seen any feasible explanation for it.
I would not rule out that lens flare may play a role. DSLR lenses often have many air/glass surfaces and may have less baffling than MF-lenses. It is also possible that MFDBs may have more efficient flare reduction in the mirror chamber than DSLRs.
Best regards
Erik
Reading Michael's editorial note at the end of the about f-stops of dynamic range, the question that comes to my mind is - will it always be this way?
Is there something intrinsic to how MF digital backs are made that causes them to have better dynamic range?
If it is simply size, then why haven't we seen a decline in dynamic range as photosites have shrunk in DLSRs?
If this is a result of sensor technology improving, then shouldn't it be possible for Canon/Nikon/Sony to churn out a DSLR with large photosites and thus higher dynamic range?
Or perhaps one might ask, why hasn't Nikon been able to reach a higher dynamic range with their lower MP count modern DSLRs?
If it isn't photosite site, is this the difference between CMOS and CCD?
Or is it something else?
I clicked on through to the cambridge colour link and whilst they discussed what dynamic range was and how it affects pixels, they didn't try to explain why the numbers are what they are.
I'm not yet ready to accept that because the camera is 35mm must mean that it has half the dynamic range of a bigger camera. There's got to be a cause...
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So, Michael's "clarification" got me to thinking that just maybe it would be a good idea to test my camera out for what really is the usable dynamic range. For this test I used the ultimate in dogmeat DSLR cameras--the Olympus E-1. This isn't totally fair, though, because this camera sports a Kodak designed and built CCD sensor not too unlike some other larger sensors, but you get the idea.
Zone-10's E-1 Dynamic Range Test (http://zone-10.com/cmsm/index.php?option=com_content&task=view&id=493&Itemid=1)
I'm NOT going to tell you how many stops of dynamic range the camera has. I'd like others to tell me based on the images shown. Now, to make things even more ugly for the camera (and limiting) all conversions were done in sRGB and straight as-is by the Olympus converter software. On the second and third pages I do include conversions maximizing highlight and shadow recovery.
I'd think that based on the images in this test, that the E-1 is capable of more than six stops of "usable dynamic range" but I'll let you experts tell me.
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Hi,
No DR actually means that the print would be uniform gray....
Best regards
Erik
The reason I don't want to get caught up in the exact DR difference between a P65+ and a highest end DSLR, is that there may well conceivably be, in some way, a 6 or 7 stop difference.
I can't predict where the proof may come from. I can't imagine where it may come from. But it may be out there. Who knows? Stranger things have happened.
What I am absolutely certain of is that from 30 feet (10 metres), you can not tell with any certainty whether a 10x8 print was taken with a MFDB or a DSLR. And I would claim that given most normal circumstances, you probably wouldn't be able to tell the difference between the same scene taken with a MFDB and an iphone. My iphone would by definition have close to no DR, so the difference would be the whole 13 stops.
I was drinking Sangre de torro 2003 reserva, now I'm on the yellow tail merlot.
goodnight all
Stefan
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sorry, one more point...
I tried this the other day after starting the thread....to put things in perspective, so to speak....
Looking at a 10x8 print from 30 feet is the equivalent in size of looking at your thumbnail at arms length. Try it.
So, I printed one of my phase files 1x1 cm and one of my DSLR files 1x1 cm and glued them to my thumbnails.
I viewed them at arms length, and my 7 year old daughter who was looking over my shoulder, said to me, "daddy, I can't tell the difference between those two prints on your thumbnails"
Therefore I must come to the conclusion that there is no difference between the DR of my MFDB and my DSLR.
This is purely anecdotal evidence, but I had to agree with my daughter at the time.
goodnight again,
Stefan
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Interesting. I have a few questions to ANYONE, including the writer of the article.
1. Has ANYONE really tested CURRENT Dslr's ....lets say the D3X....DIRECTLY against the ....say....P65+ unit to see what TRUE DR numbers are?
2. If so please present your findings and if you have any proof at all, please let them flow.
My hunch is....DSLRs are better than the Mark assumes (as he says others SHOULD not talk if they havent done the tests....then goes on to say that his DSLR data is not from a test like he reccomends, but from heresay from the company.) I think this is why so many people are ticked off. Oh and the 30 feet comment.....ok guys....for somone to say WHOA! look at the DR on that picture....well that is absolutly SILLY. No one knows how much DR is in a shot they know nothing about....come on. Even if it was said....it would be totally silly that the person had all the information to really make a definitive statment about the DR of the picture printed.....no more than a person would be able to comment on noise quality of a camera from a downsized picture posted on the web.
About DXO....well they are off quite a bit, but in all fairness, they are off quite a bit consistantly. As such even if the numbers are off based on the mechanical and not human perception testing procedures, apples are compared to apples with the test. So with DXO numbers being off from real world...I would say that it would be quite silly to assume that the numbers are BETTER on the MF kit, and WORSE on the DSLR kit.....thats just not very logical. Actually that would sound very emotional.....and emotions rarly have any merit when your on the hunt for facts.
So my proposal is, somone who has both cameras.....DO THE TEST.....put this all to rest. Sure the emotional ones will continue to argue over testing procedures, etc.
I know I get about 8 full usable stops of info on my D300 using 14bit RAW files. A bit more than assumed in the article. I expect MF backs to do better than my D300.
I suspect the real numbers with the D3X and MF kit to be more like D3X 10 usable stops, and a solid 12 - 12.5 usable stops of DR for the MF kits.
Anyone want to place any bets?
Roman
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Hi Erik,
Well, exactly. So we're talking about tonal differentiation, not black and white.
Because the difference between black and white will always be the same. Which means that these tonal subtleties will be lost at 30 feet away.
Downres your favourite photos to a few inches by a few inches on your monitor and you will have to up the contrast and sharpen for the image to have the same effect.
From a distance, prints will behave the same way. If you want to view 10x8 prints from 30 feet away then you will have to up the contrast and sharpen in the same way to make it look better to the human eye- thus getting rid of any tonal advantages the MDFB print may have had.
cheers
stefan
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that will be just +/- 2.5 stops in CaptureOne, right ?
with the "Exposure" tool, yes. But there's also "Brightness", "HDR", "Levels", "Curves" ...
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Fred.
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And the debate rages on!
The sooner someone takes a MF digital and DSLR outside, takes a few shots and throws them up, the better!
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What’s going on here? This thread contains enough BS and recycled rubbish to fertilse the Sahara dessert.
Does anyone seriously think that whatever DR is, if there was truly a 6 stop difference we’d all not be aware of it? Even 4 stops.
Many of you guys, like me, own state of the art DSLRs and MFDBs, have done for a few years and pretty much know how to get the best out of them and their software. Yes, there’s a difference in some parameters, and clearly MF has the edge in some aspects of image quality, but 6 stops of anything? Get real. And don’t try to counter with the ludicrous argument that “If you can’t see it then that’s ok but we can.”
The fact that Michael and a few supporters continue to say it has, coupled with obviously contradictory statements which are then justified in a way that would impress even a politician, makes me seriously worry for their well being.
Sorry guys but this sort of thread devlaues LL massively.
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dpreview include an empirical DR analysis in their camera tests. They come out with 8.5 to 9 stops of DR for DSLR jpegs, and 11 or so for the RAW output with tone curve optimization. I don't see any MFD tests on their site, but the figures for DSLR's are pretty good.
Also, I don't 'get' the point of the print-at-30-feet story. Firstly, the whitest whites and blackest blacks are set by the print technology, and anyone can adjust a low-DR image file to max white and black. It's only the amount of subtlety in between that would vary with DR and that would require close inspection to distinguish.
Secondly, a high-DR image runs the risk of appearing 'flat', not more impressive.
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Gentlemen, at least I've learned a specificity of the english language.
In my native language, french (and the french speaker can confirm it),
we would use 30 feet to express a feeling, not a distance in itself.
If someone write: "on peut voir la différence à 10 mètres" (we can see the difference from 30 feet), everybody would immediatly understand that this person is not talking about absolute measure distance but about transmiting a sensation of clear differences from a distance.
So in my language, we can see the difference from 30 feet=there are clearly visible differences.
Not that this has been scientificaly mesured with a laser
I thought that the language of precision and absolute was german, I'm surprised and delighted to learn that it is actually english.
Sincirely, I found that many of the attacks about that have been cynicals and made in order to demostrate one's ego superknowledge, but I see that I was wrong and basically I know now that it is because the english language does not tolerate vagueness and non-scientific concepts...This is a dispache from the field.
Now, about the DR stops, it has been writen from ages around the web that those differences are not just one stop or two, and it did not provoque this tsunami. But because we are in an high end scientific community, where the all world is waiting the very last of Lu-La posters researchs in order to be informed by the very gods of photography, this has made history and now we came to the conclusion that this web site has damaged its reputation...
If you find that we could fit an entire desert with rubbish I certainely beleive so.
I'm sure that more than one engineer working in photography research had a good laugh seeing many of the vague arguments with absolutely no proof in images, made by those who claim rigor and complained about the exageration.
I also noticed that the only woman who post here has made a real wised contribution with a draw, saying with a welcome tint of humor: a mistake? who cares?...but testosteron has occured as always and now I also understand more about the reasons of the wars and desasters that happened to the human race. I think we really need more women in power.
Regards,
Fred.
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Gentlemen, at least I've learned a specificity of the english ...
So in my language, we can see the difference from 30 feet=there are clearly visible differences.
Not that this has been scientificaly mesured with a laser
I thought that the language of precision and absolute was german, I'm surprised and delighted to learn that it is actually english.
Close Fred - as if Fred were you're real name!
It means both "exactly 30' measured with a laser", AND "with your nose pressed hard against the print". But it also means "and no distances, however precisely specified, in between."
It is really the theory of limits, like calculus and quantum physics. The intermediate remains precisely undefined. You can, however, "vaguely undefine it", as in French.
Have you not listened to talk radio - surely everyone listens? - and heard them talk about the Fascist Socialists? Then you have my biologist brother-in-law, who is also a creationist, and believes the earth is 6,000 years old (true story. )
How else can one explain this whole thread?
Cheers, Mr Alexis de Tocqueville! And you thought I did not watch The Pink Panther! Ha!
M.
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Close Fred - as if Fred were you're real name!
It means both "exactly 30' measured with a laser", AND "with your nose pressed hard against the print". But it also means "and no distances, however precisely specified, in between."
It is really the theory of limits, like calculus and quantum physics. The intermediate remains precisely undefined. You can, however, "vaguely undefine it", as in French.
Have you not listened to talk radio - surely everyone listens? - and heard them talk about the Fascist Socialists? Then you have my biologist brother-in-law, who is also a creationist, and believes the earth is 6,000 years old (true story. )
How else can one explain this whole thread?
Cheers, Mr Alexis de Tocqueville! And you thought I did not watch The Pink Panther! Ha!
M.
that is exactly why I did a Leica M clouseau inspector one day here...
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This thread has been fun (for some, not so much for others), but it's time to draw it to a close as it has gotten too long and tangential.
Mark Dubovoy and I have discussed the controversy and decided to remove the offending paragraph. It was a bit hyperbolic and off-hand, and not within the spirit of the rest of the review.
I have therefore added the following section to the review. Please feel free to start a new thread on this topic, as closing it is not intended as censorship, just a bit of good housekeeping.
Paragraph Removed – Editor
The paragraph below was part of the original article. It caused quite a bit of controversy on this site's forum and elsewhere. I initially added a comment to the bottom of the article, but that wasn't sufficient. Too many people's favourite ox had already been gored.
Please consider the paragraph below to be removed. There's no point in actually removing it, because once on the net, things last forever, and undoubtedly some of the zealots would consider it a coverup if we did so.
The reason that Mark and I have decided to remove it is not because we don't agree with its basic sentiment, but because it is serving as a distraction for the main point of the review, which is a comparison between two different medium format backs.
There is wide agreement among photographers that use or have used both formats that MF has an advantage of several F/stops in DR versus the small cameras. The precise number will vary depending on the specific camera and back being compared as well as the comparison methodology, but the difference is quite noticeable in actual images. From 30 feet away? Maybe not. Let's just chalk that phrase up as a bit of editorial hyperbole rather than something intended to be taken literally.
The issue of the differences between medium format and 35mm is a fascinating one though, and Mark and I intend on pursuing it in greater depth in the days ahead, and with more rigour than with a throw-away line or two.
Michael