DR, DxO, DSLR, MFDB, CMOS, CCD

[eronald]

But then, comes immediatly a question.

If the D3x is that impressive, and in many aspects supposely matches or equal the highest MF backs,
considering its much lower price, its better distribution and universality, and that can even shoot video,
why the MF users are not selling their gears like hot-dogs and go all for the D3x?

(not talking about the one who use regularly view and tech cameras but MF cameras)

Well, the June issue of Nihon Camera has a couple of full-page landscape images from the D3x and the Pentax. And on seeing them, I prefer the D3x image. Both are Jpeg images. Which is a bit surprising since I own both a Phamiya and a D3x, and the Phamiya outresolves the D3x considerably.

Edmund

[ErikKaffehr]

Ray,

There is also a healthy advantage in resolution. It matters if you make large prints...

Best regards
Erik

Well said, Bart. There's a lot of processing that takes place between a RAW capture and the final print. I remember a few years ago attempting linear conversions to retrieve maximum highlight detail from certain images, before ACR hit the market. I soon gave up on it. It was too difficult to get a satisfactory tonal result across the whole image when starting with a linear conversion.

Issues also raised in this thread about the DR limitations of the the monitor, the limitations of web-based jpegs, and particularly the DR limitations of the print, are complete red herrings.

When attempting to compare a particular aspect of camera performance, such as DR, it's standard practice that one should at least attempt to keep the processing similar, such as noise reduction, sharpening, saturation and vibrancy, hue and WB, and of course proof settings with regard to paper/printer profile, when making a print.

There are differences in the way certain RAW converters handle image files from different models of cameras. I know, for example, that Bibble can produce slightly sharper results from my Canon RAW images than ACR. But I know also that this slight edge in resolution is at the expense of noise. ACR images are a little softer, or blotchier, but have clearly less noise. If I apply some noise reduction to the Bibble conversion, it looks pretty close to the ACR conversion.

Nevertheless, there are subtle differences, and anyone may prefer one particular RAW converter to another based on personal taste, and even image type, such as portrait or landscape.

However, the issue in this thread is not about subtle differences in DR due to differences in the default noise reduction of certain RAW converters, but is about huge differences in DR as reported by certain reviewers.

What's the explanation?

There are a number of explanations that I think may all be true to some degree. I'll list a few, but please don't think I'm pointing the finger at anyone. We're all human, but some of us are more scientifically rigorous than others. And even the scientifically rigorous are not neccessarily scientifically rigorous all the time, in all circumstances. Even Einstein made some flaws of judgement, perhaps due to his religious proclivities. (I'm thinking of, "God does not play dice", in relation to the  theory of Quantum Mechanics).

1. MFDB manufacturers are struggling to be viable. Their products are ridiculously expensive in relation to the increased performance over a good 35mm DSLR, and they need all the good publicity they can get. A bit of hyperbole from a few reputable photographers is much appreciated.

2. Image is important in more ways than one. The professional photographer needs to impress his clients. An expensive MFDB system may do the trick.

3. Less discerning photographers tend to follow the 'big boys'. If their successful mentors or idols are using particular equipment, they will tend to follow and buy the same equipment. It's all too human. There's a lot of irrational behaviour in human society. When their purchasing decision has been made, mortgaging their house to buy a complete MFDB system, any criticism of their excessive expenditure will be met with strong, subjective statements supporting the superior performance of their equipment.

There can be no objective testing in such circumstances, because such testing would reveal such a marginal increase in performance, disproportionate with the  price paid, it would cause distress. We all like to kid  ourselves on occasions, including  me.

4. There's a tendency to group the performance of all 35mm DSLR together, and compare an unspecified experience of 35mm performance with MFDB, which may exclude the best 35mm performer, the Nikon D3X, but include the best MFDB performer, whatever that may be.

Should I continue? I don't want the thread to be closed.

I'll add that I've never found much difficulty in determing the DR capability of a camera. Everyone who can afford a good camera probably lives in a house or a flat, doesn't he/she? I mean, he/she who owns a P65+ or D3X is not likely to be a street dweller.

In which case, just photograph your living room on a sunny day and expose for the brightest clouds out of your window. It's terribly simple. If you want to be really thorough, you could place a few very detailed objects and artifacts in the  living room, even a newspaper.

Having exposed correctly to get all the cloud detail, using your MFDB and D3X in ETTR mode, then examine the detail in your living room. The camera that provides the greater detail in your living room has the better DR.

The fact that a true ETTR may be difficult to achieve, is another red herring. Just do it. If the clouds are blown, take another shot, and another shot, till it's right.

[John R Smith]

Actually, personally I don't give much of a monkey's for DR. All I really worry about is blown highlights, and that is a matter for correct exposure. Working in B/W, most times the last thing I want is lots of shadow detail. I usually like my shadow areas to be black, or nearly so, so I often a clip a lot of DR out of the print quite deliberately.

But one advantage of my ridiculously expensive MF digital back, which I don't see mentioned here, is the abilty to make really severe crops (or selectives, as we used to call them). I can chop just a section out of the frame and still have 20MP, quite enough for an A3 print or more. Which is nice to have.

John

[bjanes]

Ray,

There is also a healthy advantage in resolution. It matters if you make large prints...

The increased resolution of MFDBs is a distinct advantage for large prints, but one can gain similar resolution by stitching with a dSLR as demonstrated by Bernard with his exquisite photos of Japanese mountainous sites. Stitching can only be used for relatively static objects and is a pain, but so would be backpacking MFDB gear into the mountains. Photography involves a number of judiciously chosen compromises. Contrary to the suggestion of an injudicious earlier post, Bernard has chosen what is best for his purposes and is not married to his D3x   .

As shown by Ctein, Roger Clark and others, the resolution of the even MFDBs is insufficient for really large high resolution prints and stitching, a large format scanning back or large format film may be required.

Regards,

Bill

[fredjeang]

Actually, personally I don't give much of a monkey's for DR. All I really worry about is blown highlights, and that is a matter for correct exposure. Working in B/W, most times the last thing I want is lots of shadow detail. I usually like my shadow areas to be black, or nearly so, so I often a clip a lot of DR out of the print quite deliberately.

But one advantage of my ridiculously expensive MF digital back, which I don't see mentioned here, is the abilty to make really severe crops (or selectives, as we used to call them). I can chop just a section out of the frame and still have 20MP, quite enough for an A3 print or more. Which is nice to have.

John

John,
I could have written exactly the same lines. I have same experience with the DR and totally agree.
Generally I often clip a lot of DR also.

[ErikKaffehr]

Hi,

The reason that this discussion was started was to find out if there is a physically feasible explanation for the purported 4-6 stop advantages in DR with MFDBs over DSLRs.

Regarding the importance of DR it's a different issue and your mileage may vary.

Best regards
Erik

Actually, personally I don't give much of a monkey's for DR. All I really worry about is blown highlights, and that is a matter for correct exposure. Working in B/W, most times the last thing I want is lots of shadow detail. I usually like my shadow areas to be black, or nearly so, so I often a clip a lot of DR out of the print quite deliberately.

But one advantage of my ridiculously expensive MF digital back, which I don't see mentioned here, is the abilty to make really severe crops (or selectives, as we used to call them). I can chop just a section out of the frame and still have 20MP, quite enough for an A3 print or more. Which is nice to have.

John

[JeffKohn]

But one advantage of my ridiculously expensive MF digital back, which I don't see mentioned here, is the abilty to make really severe crops (or selectives, as we used to call them). I can chop just a section out of the frame and still have 20MP, quite enough for an A3 print or more. Which is nice to have.

Probably it wasn't mentioned because the original intent of this thread was not to debate advantages and disadvantages of MFDB versus DSLR. I don't think anybody here is claiming the MFDB's have no advantages at all.

The question under debate is whether there's a huge gap in real world, usable dynamic range, and if so what explains that gap and why does it disagree with the engineering measurement of DR which shows the backs and DSLR's to be quite close in DR.

Whether it's Mark D's 6-stop comment, or the statements by Michael and some others that there's a 3-4 stop advantage, none of these claims have been backed up with any sort of compelling arguments based on facts, tests or even logic.

[John R Smith]

Probably it wasn't mentioned because the original intent of this thread was not to debate advantages and disadvantages of MFDB versus DSLR. I don't think anybody here is claiming the MFDB's have no advantages at all.

The question under debate is whether there's a huge gap in real world, usable dynamic range, and if so what explains that gap and why does it disagree with the engineering measurement of DR which shows the backs and DSLR's to be quite close in DR.

Yes Jeff and Eric

I was somewhat off-topic here, and my apologies. However, I know this debate is all terribly compelling and so on (and we seem to keep having it, in one form or another), but what I don't understand is why it seems to matter so much to all you chaps. I mean, what has it actually got to do with real-world photography? We have always had less DR in the negative and in the print than our eyes can see in the real world. A stop here or there between one film and another or one sensor and another may be really interesting to the anoraks of this world, but once you are out there climbing over hedges and struggling through the brambles, a bit of cloud cover to the north will fill the shadows and make more difference to your DR than the ruddy sensor ever will.

As photographers we spend our time working with and considering the quality of light. Sometimes we can control it, in a studio, sometimes we choose not to and grapple with the light nature bestows upon us. It seems to me that all the DSLRs and MF backs and films made today have plenty of DR for pictorial photography. Unless perhaps you always work in the middle of the Arizona desert at noon under a cloudless sky. A certain amount of dynamic compression is what makes a photograph look like a photograph - it is part of the style and visual language of of photography. Which is perhaps why these HDR images we see now look so horrible.

John

[Bart_van_der_Wolf]

I was somewhat off-topic here, and my apologies. However, I know this debate is all terribly compelling and so on (and we seem to keep having it, in one form or another), but what I don't understand is why it seems to matter so much to all you chaps. I mean, what has it actually got to do with real-world photography? We have always had less DR in the negative and in the print than our eyes can see in the real world.

It matters a lot because it opens up possibilities we never had before. It matters alot because it allows a level of realism in my images I never had  before. It matters a lot because I can shoot at ISO levels I never could before with such a level of quality. You cannot be serious in preferring the limited dynamic range of slide film, can you? So, removing a weaker link in the chain matters, a lot.
 

A stop here or there between one film and another or one sensor and another may be really interesting to the anoraks of this world, but once you are out there climbing over hedges and struggling through the brambles a bit of cloud cover to the north will fill the shadows and make more difference to your DR than the ruddy sensor ever will.

You forgot to mention the use of a properly dimensioned lens hood, and no filters, and superior optics, but that's not the issue at hand.

Again, you are missing the point of this thread, it is about understanding the wild claims of superior DR where there is demonstrably none, or very little at best in a few isolated cases when downsampled.

Unless perhaps you always work in the middle of the Arizona desert at noon under a cloudless sky. A certain amount of dynamic compression is what makes a photograph look like a photograph - it is part of the style and visual language of of photography. Which is perhaps why these HDR images we see now look so horrible.

That is also not true, it's the poor tonemapping that gives HDRI a bad rep. You also fail to see that the huge interest in HDRI apparently suggests something was lacking, namely DR. That's why the debates are here, most of us are seeking to improve our image quality.

Cheers,
Bart

[John R Smith]

That is also not true, it's the poor tonemapping that gives HDRI a bad rep. You also fail to see that the huge interest in HDRI apparently suggests something was lacking, namely DR. That's why the debates are here, most of us are seeking to improve our image quality.

Cheers,
Bart

In my own opinion (and it is only mine) increased DR and "improved image quality" are not at all the same thing. At least, if we are talking about pictorial image quality. What is it that you want your pictures to look like? Exactly like reality? Surely reality is the starting point for art, not the destination.

John

[Bart_van_der_Wolf]

What is it that you want your pictures to look like?

Hi John,

I don't want them to look like anything. I want them to evoke the emotion I want, without the technical hurdles or obstacles making my life more difficult than need be. Unnecessary noise, banding, blocked shadows, and other technical imperfections usually distract from the message being delivered.

Now, back to the topic.

It is my impression that some of the perceived differences attributed to DR, are actually caused by differences in the MTF. That's why an objective DR determination cannot fully explain the claims. There may also be a difference in the contribution of veiling glare.

Cheers,
Bart

[ErikKaffehr]

Hmmm,

Better resolved texture? I was not thinking about that! Veiling glare is a quite obvious culprit. Add to that the issue Emil martinec discussed on CGA and color transformation and things may start to add up.

Best regards
Erik

It is my impression that some of the perceived differences attributed to DR, are actually caused by differences in the MTF. That's why an objective DR determination cannot fully explain the claims. There may also be a difference in the contribution of veiling glare.

Cheers,
Bart

[Ray]

Ray,

There is also a healthy advantage in resolution. It matters if you make large prints...

Best regards
Erik

Of course, Erik. The higher resolution from a sensor with a higher pixel count is very important when viewing large prints from the same distance you would normally view a small print.  

I think it's interesting that there's a very good parallel in the Canon 35mm world, to the DXO comparison between the D3X and the P65+. It's the comparison between the 20D and the 5D2. I don't think anyone would claim the 5D2 has a 4-6 stop DR advantage over the 20D.

In both situations we have a larger format camera with the same pixel pitch as another smaller format camera, and in both situations the two different formats vary in size (or at least in area) by the same degree. Shooting the same scene with the 20D and 5D2, using the same lens, then cropping the 5D2 shot to the same FoV as the 20D shot, produces not only the same size of image but the same quality of image, approximately. Tonal range, color sensitivity, SNR at 18% grey, are all about the same. What differs slightly is the DR. The 5D2 has a slight edge in DR, perhaps due to a further narrowing of the gap between microlenses, but so small (about 0.25 of a stop) one might not notice it.

Likewise, using the same lens with the D3X and P65+ (or lenses of equal focal length and optical quality, as far as possible), then cropping the P65+ shot to the same FoV as the D3X shot, should result in images of similar quality. Perhaps the P65+ shot will be very marginally crisper due to its lack of an AA filter. However, tonal range, color sensitivity and even SNR at 18% grey should be very similar.

The significant difference between these two sets of comparisons, according to DXO Mark, is the way dynamic range varies. The D3X image should have a whopping 1.75 stops greater DR than the cropped P65+ image. Clearly the D3X is in a league of its own. The D3X exceeds the DR of the P65+ (at the pixel level) by a greater degree than the P65+ exceeds the DR of the 5D2 (at the pixel level).

But to raise your question again; how do the 4 to 6 stop claims arise when only a 1 stop DR advantage should apply in relation to the average full frame 35mm DSLR, according to DXO? I think perhaps we should look at the way C1 handles the P65+ RAW image. Maybe there's some magical algorithm in the C1 software that works only with Phase backs, creating an illusory 4 to 6 stops DR advantage   .  Or maybe owners of MFDB systems are so pissed-off at the fact that their expensive cameras have such lousy performance at high ISO, that they just can't resist stirring the pot and having a dig at owners of cameras which do have superb high-ISO performance, by occasionally making outrageous statements about the illusory 4-6 stop advantage which no-one seems to be able to demonstrate  .

Seriously, I believe it's the case that most photographers who use MFDBs are professionals who constantly need to impress their clients. It would be counter-productive and a waste of time for any of them to demonstrate that a D3X really is capable of delivering more DR than a P65, or that the DR advantage of a P65 over a Canon 35mm DSLR is only about 1 stop.

60mp is clearly much better than 21 or 24mp, and there's no doubt that on a 40"x60" print from a P65+, the veins on a model's eyeball are so much more impressive when viewed from a distance of a foot or so.

As Fred mentions, good solid blacks can be beautiful. If a professional really needs to photograph the interior of a room, simultaneously displaying the beautiful view through the window - flowers, green fields and fluffy white clouds all correctly exposed - he's probably in a position, as a professional, to bring in a truck-load of lighting, or even apply a film gel to the glass of the window to reduce the brightness of the outside scene. The result is likely to be more impressive than a single shot from a D3X, at least on a large print. Also, if dynamic range is likely to be an issue, then a 1 stop advantage is not likely to be sufficient to produce a good, professional result. Bracketing of exposures and merging to HDR may be a minimum requirement, in the absence of additional lighting, whatever camera is used.

[fredjeang]

Despite that I gave up when curves and graphics started to show up, I find this thread really good, informative and as an example of
the high level and behaviour expected in this site.

Erik, the OP did a brillant moderator task to avoid out-off-topics paths. And that was not an easy topic that could have degenerated.

Many technical informations as I said, but IMO one point has not yet been answered:

In what frame should we all use the term DR, in order to be sure we are taking the same reference point.
In other words, what should we strictly understand by the DR term, and what is accepted by everybody as a relaible mesurement standard ?

If we can not reach a common field on a standard, then, weired differences will show up all the time.

IMO.

[BernardLanguillier]

A certain amount of dynamic compression is what makes a photograph look like a photograph - it is part of the style and visual language of of photography.

Very true.

I believe that the very essence of the quest for DR is in fact a quest away from the issues of digital files we have been facing for years:
- sensors are linear and don't allow any highlight recovery,
- the transition to blown areas isn't always as smooth as with film,
- shadows can exhibit weird issues like banding,
- some digital files require good manipulation discipline not to reveal their digital nature in print,
- ...

We sort of all believe/claim to be on the fore front of digital image manipulation but most of us in fact just hope to be able to get rid of these issues. DR is perceived as the one stop solve it all magic word that encompases all that.

Once the issues are solved, we are indeed back to square one where what really matters is sweet light hitting the right spot in a scene. More often than not we won't need much DR to tap into that magic moment.

Now there are of course other reasons why we keep debating:
- Some claims made by moral autorities in this community are surprising which triggers a genuine desire to see proof,
- Gear discussions are fun and can be an efficient way to stay awake in some boring meetings,
- ...

Cheers,
Bernard

[ErikKaffehr]

Ray,

Thanks for good comments. I would almost expect you pointing out the viewing distnace issue. I would add that it's working the way that we don't increase viewing distance proportionally to image size. Think of an IMAX or Omnimax theatre. One of the reasons to print big is that you can see the print at reasonable distance and still feel immersed in the picture.

One point I would like to make that peoople like Mark Dubovoy probably don't need to impress customers, more get satisfaction of doing what they do optimally. I also think they are serious in their writing.

On the other hand, Mark was quite confirmative on the 6 stop difference. I cannot explain how such a large difference could arise, therefore the topic.

Another issue is that DxO-mark is widely discredited by those who know better. I was most interested what perspective the folks familiar with image processing take on that issue.

My understanding is that it seems to be a common ground regarding DxO beeing pretty correct and usable and also that DR advantage of MFDBs over DSLR would not exceed one stop.

I also made the assumption that extensive DR would translate into good high ISO capability, and at least Emil Martinec seems to agree.

Emil and Bart also came up with some new ideas on effects which may be interpreted as DR related to CGA implementation, veiling flare and also MTF. Very well possible that all this adds up to a significant advantage in image quality.

Best regards
Erik

Of course, Erik. The higher resolution from a sensor with a higher pixel count is very important when viewing large prints from the same distance you would normally view a small print.  

I think it's interesting that there's a very good parallel in the Canon 35mm world, to the DXO comparison between the D3X and the P65+. It's the comparison between the 20D and the 5D2. I don't think anyone would claim the 5D2 has a 4-6 stop DR advantage over the 20D.

In both situations we have a larger format camera with the same pixel pitch as another smaller format camera, and in both situations the two different formats vary in size (or at least in area) by the same degree. Shooting the same scene with the 20D and 5D2, using the same lens, then cropping the 5D2 shot to the same FoV as the 20D shot, produces not only the same size of image but the same quality of image, approximately. Tonal range, color sensitivity, SNR at 18% grey, are all about the same. What differs slightly is the DR. The 5D2 has a slight edge in DR, perhaps due to a further narrowing of the gap between microlenses, but so small (about 0.25 of a stop) one might not notice it.

Likewise, using the same lens with the D3X and P65+ (or lenses of equal focal length and optical quality, as far as possible), then cropping the P65+ shot to the same FoV as the D3X shot, should result in images of similar quality. Perhaps the P65+ shot will be very marginally crisper due to its lack of an AA filter. However, tonal range, color sensitivity and even SNR at 18% grey should be very similar.

The significant difference between these two sets of comparisons, according to DXO Mark, is the way dynamic range varies. The D3X image should have a whopping 1.75 stops greater DR than the cropped P65+ image. Clearly the D3X is in a league of its own. The D3X exceeds the DR of the P65+ (at the pixel level) by a greater degree than the P65+ exceeds the DR of the 5D2 (at the pixel level).

But to raise your question again; how do the 4 to 6 stop claims arise when only a 1 stop DR advantage should apply in relation to the average full frame 35mm DSLR, according to DXO? I think perhaps we should look at the way C1 handles the P65+ RAW image. Maybe there's some magical algorithm in the C1 software that works only with Phase backs, creating an illusory 4 to 6 stops DR advantage   .  Or maybe owners of MFDB systems are so pissed-off at the fact that their expensive cameras have such lousy performance at high ISO, that they just can't resist stirring the pot and having a dig at owners of cameras which do have superb high-ISO performance, by occasionally making outrageous statements about the illusory 4-6 stop advantage which no-one seems to be able to demonstrate  .

Seriously, I believe it's the case that most photographers who use MFDBs are professionals who constantly need to impress their clients. It would be counter-productive and a waste of time for any of them to demonstrate that a D3X really is capable of delivering more DR than a P65, or that the DR advantage of a P65 over a Canon 35mm DSLR is only about 1 stop.

60mp is clearly much better than 21 or 24mp, and there's no doubt that on a 40"x60" print from a P65+, the veins on a model's eyeball are so much more impressive when viewed from a distance of a foot or so.

As Fred mentions, good solid blacks can be beautiful. If a professional really needs to photograph the interior of a room, simultaneously displaying the beautiful view through the window - flowers, green fields and fluffy white clouds all correctly exposed - he's probably in a position, as a professional, to bring in a truck-load of lighting, or even apply a film gel to the glass of the window to reduce the brightness of the outside scene. The result is likely to be more impressive than a single shot from a D3X, at least on a large print. Also, if dynamic range is likely to be an issue, then a 1 stop advantage is not likely to be sufficient to produce a good, professional result. Bracketing of exposures and merging to HDR may be a minimum requirement, in the absence of additional lighting, whatever camera is used.

[bjanes]

Hmmm,

Better resolved texture? I was not thinking about that! Veiling glare is a quite obvious culprit. Add to that the issue Emil martinec discussed on CGA and color transformation and things may start to add up.

Best regards
Erik

Finally, we are looking at parameters other than DR in an attempt to explain the differences between the two formats. The DR theory is the emperor who has no clothes. Veiling glare has to do with the lens and the baffling in the camera box and not the format per se. Emil's comments on CGA and color transformation are right on and explain the DXO noted differences between the Canon 500D and Nikon D5000, where the Nikon has superior spectral sensitivity to the Canon; both cameras have similar relative sensitivities.

However, in the comparison of the Nikon D3x and Phase One P65+, the Nikon has better spectral sensitivity in the red channel, but an unfavorable relative sensitivity, requiring a larger white balance multiplier. The net effect is more or less a draw and the two cameras have a similar color sensitivity. As Emil noted, these are engineering compromises.

[attachment=23095:ColorSensPrnt.gif]

IMHO, it is a mistake to refer to dSLRs as a homogeneous entity, as if there is no difference between the d3x and a Digital Rebel. Likewise, there are significant differences between MFDBs. It makes more sense to compare the best dSLR (D3x) to the best MFDB (P65+). The P65+ and D3x have pixel sizes of 6 um and 5.8 um respectively, and the D3x has slightly better per pixel performance, but the P65+ has more pixels. Four to six f/stops of DR is 16 and 64 times respectively, and such an advantage is unlikely from a mere 2.5 x in sensor area.

Regards,

Bill

[NikoJorj]

I believe that the very essence of the quest for DR is in fact a quest away from the issues of digital files we have been facing for years [...]

It is very true indeed that the very different tonal characteristic of the media made asked for an athletic gymnastic during the transition ; however, I'll rephrase that in a slightly different way (according to my personal history at least).
I shot slides in the last millennium, having no practical access to a color darkroom, and when transitioning to a dSLR a few years ago, I really felt like relieved of a burden : passing from a minilab print made from a slide (5-6 stops?) to an inkjet print made from an edited raw file (8-9 stops? these numbers are an uneducated guess only), my images could really stand much closer to what I saw especially in the shadows, which is very practical in my boringly figurative style (or lack thereof).

So I'd say the current quest for DR may have been triggered by the leap forward made by digital files in the color area : it showed that huge progress could be made, and showed also there is still some room for improvement - I'd say that my eyes have a DR of about 15 stops.

Veiling glare is a quite obvious culprit.

Sensor DR is a desirable thing but I'd also think that veiling glare is the weakest link relative to DR in many real-world situations, especially with wide-angle lenses, making sensor DR irrelevant past a certain point (which I've sometimes seen quoted in the 10-12 stops range, ie exactly where the DR war actually starts).
There are more and more lens reviews online, but I'd love to find one that measures or at least shows some things in this area. A shoot with a controlled (studio) lighting in or near the frame and details to unshovel in the shadows should do the trick?

[ErikKaffehr]

Hi,

On the first issue I'd agree that neither MTF nor veiling glare is are sensor related issues. Both may help to explain a visible difference between camera systems A and B in rendering texture in the dark parts of the image.

I fully agree that we cannot see  either DSLRs or MFDBs as homogenious entities, even if some contributors seem to take that liberty. Mark Dubovoy compared P65+ and Canon 1DsII. It certainly seems to be the case that Nikon D3X stands out amongs DSLRs. The question is also in this case, how did they achieve that. On the other hand, the advantage the D3X has is consistent with DxO data.

Best regards
Erik

Finally, we are looking at parameters other than DR in an attempt to explain the differences between the two formats. The DR theory is the emperor who has no clothes. Veiling glare has to do with the lens and the baffling in the camera box and not the format per se. Emil's comments on CGA and color transformation are right on and explain the DXO noted differences between the Canon 500D and Nikon D5000, where the Nikon has superior spectral sensitivity to the Canon; both cameras have similar relative sensitivities.

...

IMHO, it is a mistake to refer to dSLRs as a homogeneous entity, as if there is no difference between the d3x and a Digital Rebel. Likewise, there are significant differences between MFDBs. It makes more sense to compare the best dSLR (D3x) to the best MFDB (P65+). The P65+ and D3x have pixel sizes of 6 um and 5.8 um respectively, and the D3x has slightly better per pixel performance, but the P65+ has more pixels. Four to six f/stops of DR is 16 and 64 times respectively, and such an advantage is unlikely from a mere 2.5 x in sensor area.

Regards,

Bill

[JeffKohn]

I was somewhat off-topic here, and my apologies. However, I know this debate is all terribly compelling and so on (and we seem to keep having it, in one form or another), but what I don't understand is why it seems to matter so much to all you chaps. I mean, what has it actually got to do with real-world photography? We have always had less DR in the negative and in the print than our eyes can see in the real world. A stop here or there between one film and another or one sensor and another may be really interesting to the anoraks of this world, but once you are out there climbing over hedges and struggling through the brambles, a bit of cloud cover to the north will fill the shadows and make more difference to your DR than the ruddy sensor ever will.

As photographers we spend our time working with and considering the quality of light. Sometimes we can control it, in a studio, sometimes we choose not to and grapple with the light nature bestows upon us. It seems to me that all the DSLRs and MF backs and films made today have plenty of DR for pictorial photography. Unless perhaps you always work in the middle of the Arizona desert at noon under a cloudless sky. A certain amount of dynamic compression is what makes a photograph look like a photograph - it is part of the style and visual language of of photography. Which is perhaps why these HDR images we see now look so horrible.

Personally I think there's more to photography than just the soft, filtered light of the magic hour, but that's what most Velvia photographers limited themselves to because they didn't really have a choice with such a contrasty film. And even in those conditions, the scene contrast often required using grad filters, which IMHO look stupid when their use is apparent (which is more often than not).  The 6-stop range of slide film was not a positive, it was something that photographers had to make do with because they wanted the other benefits of slides.

I think all kinds of light can be "good" light depending on the conditions and your subject. Having more DR to handle the contrast in more scenes is a good thing. You can always increase contrast in post if you want, but you can't bring back what was lost so given I choice I'd rather have more DR than less.

You won't get any argument from me about overdone HDR, but that really has nothing to do with camera DR, that's just a matter of bad processing (and maybe poor taste).

Bottom line is that with the D3x, I don't have to bracket multiple exposures as often as with my old cameras, which is definitely a benefit.