Apply CCC color correction LUT on EXR

I am trying to import the ccc files that accompany my EXR sequences in order to make our editorial presentation.

At first, I thought it will be: Look node → import ccc and voila, but of course the result cc output was different from their QT reference.

I am using a ColorManagement node as a View Transform to be able to see my EXR as their QT ref.

Any advice?

I am tagging my exr as “scene-linear Alexa Widegamut”, creating a rule inside color management using:
Linear Alexa Wide Gamut / ACES 1.1 SDR-video (Rec 709 limited) / scene-linear Alexa WideGamut / Any.
My project Working Colour Space is LogC (v3-E1800) AlexaWideGamut.

Typically the luts are added to the original camera negative file. They are hardly ever added on linear. so try to add your LUT after Input Transforming to Camera/Alexa Wide Gamut.

Thanks for clarifying this Andy, but when I import my EXR sequence, I tag it already to SceneLinear Alex WideGamut, so in anyways it will be after… maybe I didn’t understand your tip.
Does the project color space inside Color Management Preference window changes any thing if it was tagged as Unknows or Log C / Alexa or Linear Scene Alexa Wide Gamut?

Are you looking to enable a viewing LUT @chadi
Or a CCC? Is a CCC what I think it is? Is it very much like a CDL?

If you import into the Look node to get it looking right then you can plug this in as a viewing LUT down in your colourMangement preferences.

I think @randy is right in suggesting applying the CCC to Arri Log C not the scene-linear Alexa Widegamut. How different is it looking? Badly wrong?

Just test this out by using inputTransform to jump fromlinear to Log-C:

First thing to do is get it looking the same as the reference QT then I can help you build a viewing LUT in the colourMgt node that will take the linear, convert to log and then apply the look but lets get the first problem solved first.

My current job
I have a viewing LUT that the DOP was using on the shoot. This LUT only works on the LogC footage but I have exported plates for CG and Nuke in linear so in order for the viewing LUT to work correctly for them the viewing LUT needs to do some somersaults before it will look right.

Jup, agree with everything but there is a twist when trying to match QT refs, that zi have run into many times.

Whats needed is a written writedown to how the QT ref was created, the whole colorpipeline, can you trust your cdl to be made to work in a certain place in your image pipeline? No you cant, but you can guess!

Usually it would go something like this in practice, when aces is not specified;

you start with linear/awg

  1. transform to logC/AWG
  2. apply CDL/ccc
  3. Apply rec709 LUT

or for aces->

  1. transform to acesCC(t)
  2. apply CDL
  3. Apply aces RRT+ODT (709)

you can also mix and match both ways, or apply cdl to linear data or apply cdl after the 709 lut.

so it could be anything, nothing but trial and error and best guesses, if the cdl is from onSet dailies its usually option1 , but maybe they also used a custom “show lut” on top and forgot to provide that.

Ive spent many nights trying to get hold of this information and in 99.99% of cases i solved it by trial and error. Or by sply making my own new luts that match their look because the cdls from set just got lost or never made and they still want me to match their dailies .

good luck, if you send me the cdl, 1 source frame and the qt ref I can help you find out whats what, its like a sudoku

Don’t forget to set the tagging to 709 when you apply the LUT. I promise it will look wrong if you forget.