Creating custom DCP profiles

DxO PhotoLab Tutorials, tips & tricks
1

I’ve been trying to create custom DCP color profiles for my Nikon cameras. I have a ColorChecker Passport reference color target and the XWrite software.

To create a custom profile one must photograph a scene with the reference card in it and convert the raw file to DNG. This DNG file is then imported into the ColorChecker Camera Calibration software which will then create the custom DCP calibration file.

DxO PhotoLab will export a file in DNG format, so that is what I used to create profiles for two cameras in two different lighting conditions. But when I applied those DNG profiles in processing raw files, the colors looked way off.

I finally thought to download the free Adobe DNG converter and use it to create the DNG files. This worked beautifully and gives me very accurate colors.

So my point is that DNG files created by DxO PhotoLab 6 do not conform to the Adobe standard.

2

You probably applied a default preset which would change your image. Export to DNG wth no adjustments and it should work.

3

Like every other RAW developer, PhotoLab applies some colour metric to input RAW files. Different developers use different metrics, which leads to what you describe: Profiles that create weird translations.

For the time being, you’ll have to use Adobe’s DNG Converter app.
Maybe PhotoLab will be able to create DCP profiles in future releases. I’d not hold my breath though.

4

they do - as you can open them in Adobe’s applications… that is the test if they conform to “Adobe” “standard” of what shall be in them … now they are not well suited to be used for “camera profiling” because you do not want to have any “corrections” applied by a raw converter ( that can’t be compensated or accounted for by camera profiling app ) and DxO PL does apply at least some (even when you try to selected NR and optics corrections only and then minimize/switch off these on top)…

5

All corrections should be deactivated when a DCP profile is created. I’ve not tested that so far. I often overexpose (less shadow noise) or use UniWB when I do reproductions and the profiles always worked under these conditions.

6

and how do you deal w/ DxO PL applying its own tone curve in addition to what is in DCP profile ? putting an explicit tone curve tag in DCP profile ( tag id 0xC6FC ) does not disable DxO PL applying its own …

7

No, I have PhotoLab set to apply no presets.

8

When it creates the profile, DPL is smart enough to ignore any previous changes to the image…but it applies these changes afterwards.

At least DPL appeared to be smart enough during my tests on macOS today.