DNG data loss: smaller gamut when compared to original RAW

[nilo]

Hi,

As there are a lot of knowledgeable people that might help me with this question too, here it goes:
 
I simply noticed, that when I build a profile from a DNG instead of a CR2, data is missing, because the gamut is quite smaller. I found this video to illustrate the problem. Don't miss the gamut comparison at the end! I contacted the author, but till now he has no explanation for this phenomena. He just stopped converting to DNG to palliate the data loss.



thanks in advance.

regards

[digitaldog]

A DNG and raw have no actual gamut until the data is rendered and encoded into some color space. Using identical rendering settings and encoding color space, there’s nothing to explain any difference in the final gamut. A DNG is a raw file.

[nilo]

A DNG and raw have no actual gamut until the data is rendered and encoded into some color space.

I am aware of that! You precisely point the finger to the problem:

Using identical rendering settings and encoding color space, there’s nothing to explain any difference in the final gamut. A DNG is a raw file.

So how come the difference in final gamut? Practically speaking, what's going on(see video)?

In Capture One, when processing one CR2, MOS etc, once straight to TIF, and once as a converted DNG (which should be the exact same data) and than to .tif, the resulting profile, produced with identical settings, will yield a quite different gamut.

[digitaldog]

I have zero knowledge of Capture 1, its settings and so forth. But unless the software is handling by default or bug, DNG rendering and encoding differently than a camera raw, there is no explanation I can give. DNG and the camera raw is just that, raw. Maybe he/she needs to use something like ACR to produce the TIFFs from the two variants and hand that off to the software building the profile. I can say with high confidence its not the DNG that’s the issue here.

[nilo]

I have zero knowledge of Capture 1, its settings and so forth. But unless the software is handling by default or bug, DNG rendering and encoding differently than a camera raw, there is no explanation I can give. DNG and the camera raw is just that, raw. Maybe he/she needs to use something like ACR to produce the TIFFs from the two variants and hand that off to the software building the profile. I can say with high confidence its not the DNG that’s the issue here.

So that's a CaptureOne question than. I'll start a new thread there.

Thank you Andrew