Lightroom-DxO Round-Trip

[tnargs]

7)Note if you go this route: Apply white balance in DXO if you have blown out highlight.

On a related issue, when I work on an image's colour in DxO, then export to LR as a DNG, the image is not even near to the same colour balance when I view it in LR compared to the colour balance I was happy with in DxO.

(Yet, if I export to LR as a JPEG, the colour balance is a match when viewed in either program.)

Why is this happening and, more importantly, what can I do to get DNG files exported from DxO to LR to retain the nice colour balance I got in DxO?

Please help.

[Dr Tone]

If you are applying color rendering adjustments in DxO you need to export as TIFF to retain your color in Lightroom.  DxO mentions this in their Lightroom plug in tutorial.

[tnargs]

I have seen that but why?  What fundamental reason prevents accurate transfer of colour using DNG files between DxO and LR?

Is it something DxO is doing? (in which case the colour will not transfer well from DxO DNG files to any other software, not just LR. Why would DxO want to do that? Why even offer DNG if it can't preserve colours?)

Or is it something LR is doing? (in which case there might be a 'cure' or 'compensation' possible, either in DxO or in LR, and I would like to know how to do that.)

BTW, using TIFF has other tradeoffs that don't suit my needs.

[Dr Tone]

I think you'll find your answer in the second post of the following thread:

http://www.luminous-landscape.com/forum/index.php?topic=68829

[fdisilvestro]

Hi,

The reason is that DXO demosaices and interpolates the file in order to apply the optical corrections. By doing this, you don't have the original RAW anymore but a linear DNG where the individual channel values have been modified. For the rest of edits, DXO uses its own metadata (as to instructions to apply to the file, similar to the LR metadata) which are not compatible with LR. If you export the DNG to LR, you loose the DXO metadata (the color and tone edits) and you start with a quasi-Raw file in LR.

Now,  why do I say you have to white balance in DXO if you have blown out highlights? Well, for some reason, DXO produces 16 bit per channel unsigned integer values in the DNG it produces. The curious thing is that all non-clipped (from the original raw) data is spread out in 15 bits (0 -32,677) and blown out data gets a much higher value that needs the 16 bits, but it is not the maximum value (65535) Why it does it I have no clue, but what happens is that LR does not consider it as a "blown out value" so if you modify the white balance in LR later on, you will get non-neutral values in those highlights. You might correct them with local edits, but in some cases it might require a lot of effort,

[tnargs]

If you export the DNG to LR, you loose the DXO metadata (the color and tone edits) and you start with a quasi-Raw file in LR.

That is not my (very limited, new to DxO) experience.

Example: I start with a RAW file that looks too blue in LR. I export to DxO and correct the colour, then export the file to LR as DNG.

If you are right, it should now look blue again when I lose the colour edits. But.... it actually looks too yellow!

[fdisilvestro]

That might be due to white balance, which does get "cooked" into the DNG. White balance =/= color edits. White balance is basically a scalar multiplication of the raw values by a factor in each channel.

Additionally, you have to verify which camera (DCP/DNG) profile is applied to the file in LR, since what you have before going to DXO might be different than what is applied when you return back, and it can make the image look different.

[tnargs]

My camera profile is not in LR so that's not it. LR uses Adobe Standard profile under the Camera Calibration tab.

[Denis de Gannes]

My camera profile is not in LR so that's not it. LR uses Adobe Standard profile under the Camera Calibration tab.

Each and every camera model that is supported by Lightroom/ ACR has its own specific "Adobe Standard profile".
By default this is the one selected, and is specific to your camera. Some cameras only have an Adobe Standard profile others have like  "Camera Vivid, Camera Portrait etc which are additional profiles created by Adobe to emulate the particular special settings you may have chosen when shooting with your camera.

[tnargs]

That's good to know, and thanks for explaining, though in my newness to this topic, I can't see why it makes sense for Adobe LR to apply a camera profile to a linear DNG file that has been through the DxO camera and lens profiles.

[fdisilvestro]

Hi,

It is because the only thing that has happened so far is demosaicing (e.g. estimating the missing R,G or B values so that each for each pixel we get rgb coordinates, and the optical correction, which is just a geometric transformation. In essence, it is not much different than a raw, the color space has not been encoded yet nor any tone curve. It is not just LR that can open and apply a DNG profile, you could actually build a DNG profile out of one of those DNG's (if the image contains a colorchecker). The file is still in "scene referred" mode

[Chris Kern]

It is because the only thing that has happened so far is demosaicing (e.g. estimating the missing R,G or B values so that . . . for each pixel we get rgb coordinates, and the optical correction, which is just a geometric transformation. In essence, it is not much different than a raw, the color space has not been encoded yet nor any tone curve. . . . The file is still in "scene referred" mode

If you're correct, you have finally provided the definitive answer—and very succinctly, at that—to the question which prompted me to start this thread.  Moreover, and not coincidentally, your explanation is consistent with the description of linear DNG by Eric Chan cited above.  Thanks.

[tnargs]

Excellent and thank you.