Nuke14 Aces2065 logc4wide to rec509 issue

Hello, I don’t know if this is the place to post a topic to ask for a hand (thank you for your patience).

I have to set up a nuke workflow with the specs of a lab but I can’t find my way around.

Here is the production context for VFX:

source: Arri Alexa LogC4 ARRI Wide Gamut 4 (the lab indicates to provide in ACES Linear AP0 2065-1, but the meta data clearly indicates that the rush exr is in LogC4 ARRI Wide Gamut 4)

and the lab notes this to work;
ARRI Alexa, Colour order of operations for Rec.709 Quicktimes:

ACES 2065-1 AP0 => Nuke: OCIO to LogC4 ARRI Wide Gamut 4 => CDL Grade > Rec709
Show LUT (full range) Scale to Rec709 legal video range (16-235) 2.4Gamma

(this whole part is a mess ! I precise i’m a junior)

I tested by putting my project settings in aces2065, in aces cct or acescg but impossible to make an export that looks like the lab reference video.

I feel like I’m at a dead end, so someone can guide me?

Thanks in advance.



I am not sure if I understand the workflow completely correct, but it sounds to me that this could be the order of operations.


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Hello Daniel, thanks for your help.
I will test asap today!
Bests regards,

the second DOT node should be labeled as Read in as ACES 2065-1!

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I think I guessed, but thanks for clarifying anyway !
Sometimes we forget the obvious things :wink:

I will test at the end of the day; thanks again

Hello @TooDee ,
I switched AriLogC4 to Linear Arri Wide Gamut 4 and now i’m close to match the result; it’s much better but It seems there is a little shift somewhere (gamma and color) to match the lab reference.

Thanks for your help again !

The plates you receiving are in ACES2065-1 according to the spec so you need to convert these to LogCV4 apply the provided cdl and then apply the supplied display lut using the file transform nodes. This is a pretty standard ACES hybrid workflow.

Your config needs to be an ACES OCIO config so exrs are treated as ACES2065-1 currently I see the read node set as Alexa Wide Gamut v4 this is not correct they are giving you ACES 2065-1 encoded files

The read node should be set to ACES 2065-1 which will put the colour into ACES cg working colourspace of Nuke. Use a colorspace node to convert from ACEScg to Alexa LogCV4 then apply the cdl and the provided display lut. It should match the reference then.

Hello, thank you for your valuable information; I was finally able to find the solution that corresponds to what you describe!

it was necessary to put the project in Acescg; the read in Aces2065 add an ocio look transform from Acescg to Arri Logc4; then cdl and lut.
So we have a perfect match with the ref edit of the lab!!

Thank you everyone :wink: