Looking for help with color managment

Using Resolve for some base grade treatment, render out EXRs and bring it into Silhuette for the hard work, then export EXRs and bring back into Resolve.
My trouble is that the look in Silhuette is not a good match for what I see in Resolve.
The endproduct is Rec709, so i do the base grade in Rec709 and the do a color space transform to Arri before rendering the EXRs. When I bring the clip into Silhuette and select Arri colorspace I don’t get the same look.
I did a bit of study on the opencolorio website - but that stuff is far beyond my paygrade.
What is good workflow for a Resolve-Silhuette roundtrip?
Thank you.

Hi there,

OCIO is a good workflow BUT I conferred with a colleague, Ben, who is more Resolve savvy than I am. The solution is relatively simple, he says.

You need to mirror the colorspace transforms between apps. And it’s simple to do. We are using your Arri example, as that seems to be what is causing the issue.

  1. From a color managed Resolve project, render out to EXR with an Output LUT : VFX IO > Linear to ARRI LogC
  2. In Silhouette, import your footage and add it to a Session. Now we want to set up the Display so we continue to work in ARRI Log C but see the footage correctly.
  3. Turn on the Display Options at the top of the viewer (big monitor-looking button).
  4. In the dropdowns we set up the Colorspace > AlexaV3LogC. View > rec709. Gamma > 0.5
  5. Work as normal and render out from to EXR
  6. Back in Resolve, we can import the EXRs into the Media Pool. Right-click on the media and apply the mirror LUT from the one we started with : VFX IO > ARRI LogC to Linear.

Now the media should be back and looking fine. All ready to be graded in Resolve.

Remember that using LUTs in Resolve breaks the color grading concatenation chain. For best results, only apply them at the end of your chain for output and in the Media Pool (aka the start of the chain) on input.

Please Note: Obviously there are “bigger and better” workflows using OCIO and ACES. It sounds like we’re after a simple, workable solution and this is it.

Please let us know if you have any questions and we will be happy to help you.

Cheers,
Mary

Hi Mary,
When I get the media back into Resolve and apply the mirror color space transform it does look OK. The issue is that it doesn’t look the same in Silhuette. I do some color adjustments in Silhuette with Roto masks and back in Resolve it looks more or less off. It seems Resolve and OCIO don’t speak the same language.
Here are some issues I run into:

  • the color space choices in Silhuette are limited and don’t match the available color space choices in Resolve.
  • The exr export are properly tagged with the exported color space, but Silhuette ignores the color space tag.
  • I made a lookup .cube file in Resolve that matches the color space transform, but when I try to select it as a display lut in Silhuette it is ignored, nothing happens.
  • Linear Gamma is listed as a color space in Silhuette - why? Its not a color space in my understanding.
  • I try to get clued up on OCIO and run into a jungle of techno babble on the opencolorio website.
    and last: How do I use ACES in Silhuette? I don’t see the option there. Is OCIO version 2 needed for that? And how to upgraded to OCIO version 2?

Short of a “clean” solution I just make up a color grading node and use it for viewing and tweak it to get a closer match, the available view transforms just won’t do the trick.

Maybe I don’t see the forest because of the trees…
Thanks for helping.
-George

Yeah, if that isn’t working for you, I am not sure what else to do. It sounds like your work around might be a good one. Let me ask @marco if he has any ideas on this one.

Silhouette ships with a stock OCIO configuration. You can download and use the ACES OCIO config file similar to what Resolve is doing here:

Part of the problem is that Resolve uses ACES and not OCIO. Silhouette uses an ACES OCIO config, so it is not the same as using two OCIO native applications. This forum post may shed some light: ACES Resolve gives different resolve than ACES OCIO - #6 by XelaCreations - Discussions - Using ACES - Community - ACESCentral

I am not sure why you are having issues loading .cube LUT files in Silhouette. This is working for me.

Thanks Marco!
What I gather is that Resolve uses math formulas to do color space conversions, whereas OCIO uses lookup tables.