ACES confusion

[sipi]

Hello

I'm confused into color management. Can someone sort this out?

I have Blackmagic Raw footage. In Davinci Resolve it is looking fine. I use ACES and sRGB Output Transform. (As far as I know I have to use Output Transform according to my monitor. I have DELL P2319H monitor and I assume it is in sRGB, not Rec.709, but correct me if I'm wrong about this.)

Now I want to export this footage, to use it in Houdini/Nuke.

I turn off any Output Transform for exporting the exr sequence. It looks like this in Davinci:

 

At this point I'm interested in getting the same image in Nuke and in Houdini what I have in Davinci.

In Nuke, if I set the Input Transform to ACES - ACES2065-1 on the Read node I get the same image, which is cool. See:

 

The problem comes in Houdini.

First of all, am I right that Houdini 20.5 doesn't require ACES installation? As far as I know it has ACES built in. ...right?

I bring in the sequence and something is off. The colors are strange. See:

 

Do you have any idea, what is going on? What should I do?

 

Regards,

Attila

 

[sipi]

Anyone who's interested, I managed to find out that I have to convert the images like this:

(e.g. using Houdini COPernicus or Nuke) (in the Write node you can choose Utility - Linear - sRGB as well)

 

 

Or!

You can save this step by setting ACES Output Transform in Davinci to sRGB (Linear) - CSC at export. Probably this is the easiest way.

 

Best wishes,

Attila

Edited April 8 by sipi

[Luxor9500]

Hi there,

That's correct in Houdini 20.5 ACES is already built-in. You can find the settings under Edit → OCIO settings. There’s also an explanation there about how different files are interpreted. For example, if the filename contains ACEScg, it will be interpreted as ACES, but I’m not 100% sure about this — I thought it was reading that from the metadata. That’s probably why, since you exported an EXR, it’s being interpreted as Linear sRGB.

Whenever I want to make sure a plate is in ACES, I export it from Resolve and choose ACEScg as the Output Transform. That way I know it’s ACES in all applications. I also include it in the filename and make sure it’s saved in the metadata.

This works for me, but if someone has a better or more technically accurate explanation, I’d love to hear it.

Cheers,
Kamil