Do you know this for a fact? I have seen some claims that the 15th and 16th bit contain only noise. If it does, then it should not give any benefit compared to converting a 14-bit file to 16 bits prior to editing.
In any case, the total quality is what is important, and numbers from a sales-brochure should not be as important as relevant as looking and measuring what is in the file.
No, I don't know that for a fact. It's difficult even to show the benefits in an image with a 14 bit A/D conversion from certain Nikon DSLRs, compared with the same scene shot in 12 bit mode using the same lens and camera.
Giving Phase the benefit of the doubt, I would expect only a very marginal IQ benefit from such increased bit depth at the A/D conversion stage. I understand also that Photoshop's 16 bit conversions from RAW files are effectively 15 bit, but I'm not going to lose any sleep over it.
As I mentioned, the greatest DR benefit from the larger files of the P65 are already shown on the DXOMark site, ie, an increase from 1/4th of a stop at the pixel level to a full stop when the P65 image is downsampled to the same size as the 1Ds3 image.
An increase in noise due to the extra degree of sharpening required of the 1Ds3 image, may have the effect of increasing that 1-stop DR advantage slightly.
It is clear in general that MFDBs have a slight resolution advantage in parts of the image that are not affected by aliasing, as a result of their lack of an AA filter.
For this reason, even when DoF considerations are not an issue, it would be considered sound practice to adjust the F stop as well as the focal length when comparing different format cameras. Everyone should know that a lens at F7.1 or F8 is sharper than the same lens at F11.
This current comparison from Phase has used F11 with both the P65+ and 1Ds3. Why?
This is tantamount to making a statement in bold letters, "This comparison is biased"
Comparing the 1Ds3 with the P45 it would be appropriate to use F8 with the 1Ds3 for the same FoV as the P45 shot at F11, using appropriately different focal lengths of lenses.
However, the P65 is a larger format than the P45, so in circumstances where F11 is used with the P65, one should use F7.1 with the 1Ds3, if one wishes to even attempt to be objective. Such an image at F7.1 would not need as much sharpening in order to match the resolution of the downsampled P65+ image.
If there are any P65+ owners out there who also have access to a 1Ds3, and who are serious about resolving this issue of the relevance of DXOMark test results, I can recommend the following procedure.
1. Select two, good quality, prime lenses of the same focal length, one that fits the 1Ds3 and the other that fits the MF camera used with the P65+.
2. Determine the T-stop of both lenses in order to avoid exposure confusion, and/or be prepared to bracket exposures in order to correctly match equally exposed frames from each camera.
3. Set the P65+ at ISO 200 (ISO 89 according to DXOMark). Set the 1Ds3 at ISO 100 (ISO 73 according to DXOMark). This is the closest match of ISO sensitivity you can get.
4. Shoot the same high-contrast scene under constant lighting conditions, from the same position, using the same F stop with both cameras.
5. Do not be confused by any significant differences in exposures that might not appear to match the slight differences in ISO sensitivity. The P65 image will have a wider FoV that might include brighter parts of the scene that are not included in the FoV of the 1Ds3.
This is why it is helpful to know the T-stop of both lenses as a starting point for bracketing.
6. Crop all the bracketed P65+ images to the same FoV as the 1Ds3 shots.
7. After cropping (and not before) match a pair of images, one from each camera, that mostly closely have the same exposure and the same highlight detail..
8. Adjust WB and levels so that both images appear similar in tonality and hue.
9. Lighten the deepest shadows equally in both images, and compare.
Now the reason for this rigmarole is in order to compare images at the pixel level, equivalent to the 'screen' mode on the DXOMark website. What DXO tell us is that the 1Ds3 at ISO 73 has approximately 2/3rds of a stop better DR than the P65+ at ISO 89, at the pixel level or screen mode.
2/3rds of a stop better DR should be noticeable if there are deep shadows in the scene that has been photographed.
If the cropped P65+ image, in these circumstances, shows significantly better detail and less noise in the shadows, then this would be good evidence that the DXOMark results have questionable relevance as regards MFDB performance.
If shadow detail appears about the same, one might have to consider if the shadows are really deep enough to reveal the DR differences. I've noticed a lot of confusion recently about the significance of an input signal of 1% on the log scale. Some people seem to think such a level is representative of deep shadows, but DXO graphs suggest otherwise.
One might also consider that manufacturing and quality control differences might be the cause of any slight variance with the DXO tests. Whilst a 2/3rds of a stop difference in DR should be noticeable, it's not particularly
I await with bated breath for someone to conduct such a comparison.