Nikon vs. Phase One dynamic range

[EgillBjarki]

According to Phase One my P30+ digital back has 12 f stops dynamic range.

Dxomark measures Nikon D3x dynamic range at 12.84 f stops.

The current top back from Phase One, the P65+ has 12.5 f stops according to them selfs.

I ask my self... Why do I have a big, slow Hasselblad H2 with a P30+ on it when the Nikon D3x is out there?

I know the P30+ has a slightly bigger sensor, little more resolution and the images are a little sharper straight out of the back but thats about it?

D3x has fast focus, really good ISO, grate screen, more robust built and MORE DYNAMIC RANGE?

One could argue that the lenses for medium format cameras have more resolution power, I'm sure thats true...

But why should I stay with medium format? What do you guys think?

[VanKou]

According to Phase One my P30+ digital back has 12 f stops dynamic range.

Dxomark measures Nikon D3x dynamic range at 12.84 f stops.

The current top back from Phase One, the P65+ has 12.5 f stops according to them selfs.

I ask my self... Why do I have a big, slow Hasselblad H2 with a P30+ on it when the Nikon D3x is out there?

I know the P30+ has a slightly bigger sensor, little more resolution and the images are a little sharper straight out of the back but thats about it?

D3x has fast focus, really good ISO, grate screen, more robust built and MORE DYNAMIC RANGE?

One could argue that the lenses for medium format cameras have more resolution power, I'm sure thats true...

But why should I stay with medium format? What do you guys think?

Did you measure the dynamic range of your P30+ with the same tool you used on the D3x (if possible?)  That would be the correct comparison in my opinion.  I find this difficult to believe frankly.

[Panopeeper]

Egill,

apart from other aspects, there are no objective comparisons between MFDBs and DSLRs, AFAIK. The DR published by PhaseOne is useful for exactly nothing.

Why don't you make some shots of some graduated grey wedge (or whatever color), or something like a color checker card, but underexposed four, five, six stops and publish the raw files to make comparisons possible? (VERY even illumination and CLEAN card or whatever is essential.)

[Dan Wells]

For what it's worth, I think DxOmark is consistently about two stops optimistic (across a number of DSLRs I know well). I have no idea how realistic Phase's number is, but I've seen numbers in the 11.5-12 stop range for MFDBs in enough places that I'd tend to believe them. I would call the D3x (which I own and think is a wonderful camera) approximately an 11 stop camera. It wouldn't surprise me at all if an MFDB had somewhere between 1/2 and 1 stop of extra dynamic range over a D3x. On the other hand, you list all the reasons I bought my D3x (when the other camera in the running was an H3DII/31). The resolution of a D3x will make a heck of a 24-inch wide print - mine has inspired me to be in the market for a 24-inch printer!
     I think the market for MF has retreated to the rarefied air above 50 MP - the D3x (and, I'm sure, forthcoming competitors from Canon and maybe others) is so good that it's hard to justify buying a 31 or even 39 MP MF system for more than twice the price any more. Fortunately, from the MF makers' viewpoint, "35mm" DSLRs are running out of room to cram more pixels on their sensors - a number of physical limits converge in the neighborhood of 25-35 mp, while those same limits will let MF have between 50-70 mp on a 36x48 mm sensor, and somewhat more than that on a P65+ size sensor...

                                                                     -Dan

[Ray]

For what it's worth, I think DxOmark is consistently about two stops optimistic (across a number of DSLRs I know well).

Consistent is the key word. It's the relative difference and not the absolute number that counts in this respect of DR where subjective elements play a part.

If we compare 3 cameras, say the Canon 5D, the Nikon D700 and the D3x, we find the DXO results for maximum DR are 10.77EV for the 5D, 11.85EV for the D700 and 12.84EV for the D3X.

The dynamic range of the D3X is a whole 2 stops better than that of the 5D. If we make an 8x12" print from both images, the D3X print will have 2 & 1/2 stops more DR than the print from the 5D. Wow!! Phwoar!! That's substantial. That's progress! Hurry up the D700X!   .

[Juanito]

Specs don't mean anything; I'd test both and see what you like better. If the D3x works out better for you, why not go with it?

John

[Ray]

Specs don't mean anything; I'd test both and see what you like better. If the D3x works out better for you, why not go with it?

John

Nonsense! Manufacturers' specs may be suspect, but tested results from a reputable company mean something. However, it's always advisable to do one's own tests, but unless you own the equipment or are able to hire or borrow the equipment, it's not possible. In addition, there's always the factor that many photographers are not necessarily competent to do precise comparisons, as is evidenced by the total confusion that's reigned so far in respect of the capabilities of the D3X.

[Juanito]

My point is that if you do a test and your eyes don't see the difference, who cares what the specs say? We can argue the numbers til we're blue in the face, but in the end it's all about the actual results that you see on paper (or on screen if that's your final result). Besides, there's other limiting factors to consider like the DR of your output device or the accuracy of the output profile or the fact clients won't notice the difference even with a magnifying glass.

Sometimes I read this forum and wonder whether anyone does any actual photography instead of just endlessly debating technoblabber.  

John

[EricWHiss]

The problem with DR measurements is that the ISO standard or definition isn't all that useful for photographers.  Most of the earlier canon's seemed to have about 11.5 or 12 stops DR but when you looked at what DR was useful with something like Imatest (scientific image testing and analysis software) the DR in the useful range was something like 8 or 9 stops (at base ISO).    The MFDB's on the other hand really do get like 11-12 stops useful DR at base ISO.    I tested the canon 1D3 with Imatest and my Leica DMR and the leica had a 1.5 stop advantage in DR over the 1D3 and though I haven't tested my p20 it has what appears to be the same jump over my DMR.  The gap is closing but the MFDB's still have more.

[evgeny]

That's interesting!!!

I want to check DR of my Sinarback, and Black/White film, and a Slide film, to better understand the real difference between these medias!

I don't have the software that you use to check DR.
Can I test DR using, suppose, a Gray Card and calibrated NEC Wide Gamut monitor, and calibrated Nikon 9000 scanner?

Thanks!

[EricWHiss]

The easiest way to have a look is to shoot a scene with shadows with the same crop. Expose to get the highlights at right without cropping and then look at the shadows.  How much detail can you see in each?  That works okay for film too but if you are comparing digital you can lift the shadows and see how much you can lift them without getting blobs, banding, or whatever.   You can also check where the shadows are on the histogram.

You can't test high DR cameras with a grey step wedge as they DR of those is not high enough.  You need to use a transmissive step wedge (like negative film) to get enough DR.   I bought mine from Stoufer and it's rated at something like 13.5 stops.  I think the printed grey step wedges are only good for 9 stops.

A good monitor has a contrast ratio of 700::1 or even now I have seen 1000:1 so that's 9 or almost 10 stops.   2^9=512 and 2^10=1024      I don't know how the translation works from camera to monitor  - someone will hopefully step in here....

[Alex MacPherson]

Feel free to unload your P30+ to me!  

[evgeny]

Eric, thank!

[EgillBjarki]

So the point being, "Numbers are not everything, see for your self".

I guess the digital back is still as good as it was when I bought it... But I'm sure you understand my thoughts.

I have the Nikon D700 as a secondary camera, maybe the best solution is to wait a year for the D700x and be happy with my gear.

All very helpful thoughts, thanks for pinching in yours!

Best regards from Denmark,
Egill Bjarki

[Panopeeper]

The problem with DR measurements is that the ISO standard or definition isn't all that useful for photographers

Measuring the DR has nothing to do with ISO. The ISO is relevant only so far as higher ISO reduces the DR. However, if the question is the maximum DR, for example for a landscape, then it does not matter which camera at which ISO has the highest DR; the only thing matters is, how high that DR is.

Most of the earlier canon's seemed to have about 11.5 or 12 stops DR

What does it mean "seemed to have"? I have never seen claimed this nonsense.

The MFDB's on the other hand really do get like 11-12 stops useful DR at base ISO

In your imagination. Although the concept of "useful DR" is subjective, I can't imagine any criteria leading to 12 stop useful DR with any present MFDB.

[Panopeeper]

Sometimes I read this forum and wonder whether anyone does any actual photography instead of just endlessly debating technoblabber

Sometimes I read this forum and wonder if luddites do any actual photography or are only complaining about topics they don't understand.

[ErikKaffehr]

Hi,

My point would be is that you should keep the gear you have. Lot of people on these forums think that MF has real benefits. Many users are overly enthusiastic when confronted with a new technology. Keep your stuff, shoot with Hassy and Nikon, if you discover that you don't really need the Hassy than you may sell it off. No one but you can make that decision.

BTW, I agree on the numbers and measurement stuff. I'm an engineer by occupation and also a bit scientifically minded, so lab data is interesting for me. Measurements are interesting and relevant, but we need to put them in perspective. In my view the best slide film, ever, was Velvia 50. Velvia had in my experience a DR of about 5 steps and was absurdly hard to scan, I loved it nevertheless. DR of ten plus steps is impressive, but I'm not really sure it matters.

I also feel there is some contradiction in the conventional wisdom that MFDBs have high DR but get noisy at high ISOs, it simply doesn't make sense to me. In my simple view DR and high ISO capability should go hand in hand.

Best regards
Erik

My point is that if you do a test and your eyes don't see the difference, who cares what the specs say? We can argue the numbers til we're blue in the face, but in the end it's all about the actual results that you see on paper (or on screen if that's your final result). Besides, there's other limiting factors to consider like the DR of your output device or the accuracy of the output profile or the fact clients won't notice the difference even with a magnifying glass.

Sometimes I read this forum and wonder whether anyone does any actual photography instead of just endlessly debating technoblabber.  

John

[Panopeeper]

I want to check DR of my Sinarback, and Black/White film, and a Slide film, to better understand the real difference between these medias!.
Can I test DR using, suppose, a Gray Card and calibrated NEC Wide Gamut monitor, and calibrated Nikon 9000 scanner?

1. You can not measure the DR of the film on existing shots, because it is not linear.

2. Re your Sinarback: the grey card is not good (you would need lots of shots). However, a grey (or whatever color) wedge, like a Kodak or Stouffer wedge, or a clean color checker card are very suitable. Underexposed three stops, very evenly illuminated, they give the different levels to measure on.

Here is how the measurements look like (this is actually a demo showing that the noise is raw channel independent). The red is at the intensity -5.17 EV (from saturation), which is not really dark, but this is at ISO 3200. The noise is 14.4%. The green sample is at -5.15 EV, the noise is 14.34%. The blue sample is at -5.13 EV, the noise is 14.07%.

[design_freak]

I understand that you already have P1. In my opinion , in general do not compare this equipment. If you compare two shots , from nikon and from p1. You will see that Nikon files are thought blurred. Dynamic range... well the only theory.
Nikon obviously is a gra camera, but not replace MFDB. Sorry...

If you want to change the equipment I recommend the new H3DII 50

Best regards,
Design Freak

[bradleygibson]

Measuring the DR has nothing to do with ISO. The ISO is relevant only so far as higher ISO reduces the DR. However, if the question is the maximum DR, for example for a landscape, then it does not matter which camera at which ISO has the highest DR; the only thing matters is, how high that DR is.

Panopeeper, Eric is not referring to the camera's sensor gain ISO control, he's referring to the International Standards Organization standard on noise measurements in photography/electronic still-picture imaging, or ISO standard 15739:2003.  This standard does contain a definition for dynamic range (in addition to definition and measurements of noise) for digital still cameras.

And Eric is correct--the standard's definition for dynamic range for digital still cameras has signficant flaws.  In fact, I just googled the standard and found an excellent paper on both the standard, and its flaws relative to digital still cameras.  You can read it at: http://doug.kerr.home.att.net/pumpkin/ISO_Dynamic_range.pdf.  Doug does a superb job covering this, so I'll leave it at that.

Egill, in the end, I'll second both Juanito's and Eric's advice (third their advice?).  The specs are only meaningful if you have a lot more information than Phase is providing.  As Eric suggested, test with a transmissive wedge or even a contrasty scene (much easier) and trust your eyes.

Remember, by the time you see an image from your raw file, the image may have gone through any number of gamma conversions, level adjustment and subjective (by your raw developer manufacturer) tweaks.  Reconstructing the imaging chain to get back to the raw data is not trivial, if you want to understand how the raw data maps to real-world quality of your images.

Just doing a side-by-side will save you more than a little time, and tell you what you really want to know, particularly if you begin lifting the shadows and looking for artifacts, again as Eric suggests.

Hope that helps,
Brad