Refreshing ACES understandings and Workflow

Hey guys, been long since I have been here cause I feel like I have grasped ACES a bit. I just wanted to confirm that everything I know is correct again.

  1. If I shoot my video in RAW ( BlackMagic RAW); I will import it to Resolve, set the colorspace to ACEScc/cct, and set IDT to no transform cause it’s RAW, sometimes I get footages in MOV files in which case I set it to the appropriate IDT for BlackMagic. I noticed that there is no IDT for BlackMagic Pocket 6K, so I resort to “BlackMagic Design”.
    After that, I set the ODT to sRGB or Rec.709 depending on the monitor I’m using and change exposure, tint, and white balance to either neutralize it by eye or use a McBeth CC24 from TechPlates ( I usually only adjust exposure).

  2. After that I set the ODT back to no transform to export it in Half-float EXRs, usually ZIPS if I’m working in Nuke and It’s high-end or Just DWAA if it’s a quick work [ I would appreciate it if someone can confirm that using DWAA causes no problems, from what I have seen it doesn’t cause any visible artifacts, even after crushing or blowing up the gamma, especially on lower compressions levels]

    ? My understanding here is that setting the ODT to no transform uses the ACES AP0 primaries on a photometric linear gamma, which I assume is the correct way to transfer any ACES file and keep maximum gamut fidelity.

    • I used to use ACEScg as my ODT to export footage to Nuke. I assumed that won’t be as much of a problem but the colors get very dull and desaturated so I stick to ACES2065-1, correct me here please if I’m wrong.
  3. After exporting, I import that back into Nuke and set the IDT of my EXR files to ACES2065-1, and everything from there on is in ACES space I assume. My view transform is the colorspace I initially corrected the footage on (sRGB or Rec.709).

  4. Then finally when finishing comp, I either :
    A) Export to final delivery straight from Nuke ( PNG seq, or ProRes MOV ) and set the ODT to Output-sRGB or Output-Rec709 depending on what I worked with. Or
    B) Export to EXR files in ACES2065-1 so I can import that back into Resolve and do some basic color work there. For a long time, I was using ACEScg to export my final comps out of Nuke to Resolve since there is usually a CG element that was rendered in ACEScg. I would love it if someone can confirm that my recent changes are okay based on my understanding.
    - After that, I set the IDT to No Transform in Resolve and the ODT to sRGB or Rec. 709 to export my final MOV files for delivery. Sometimes I set the ODT to ArriLogC or a similar log space since some editors specifically requested those and in that case, I export using DPX.

Something I would love a small explanation or confirmation of is that ACES2065-1 and ACEScg are only different in terms of gamut and not “gamma”. So using either one for file transfer is okay if I’m aware of what I’m doing.
Thank you for reading through this and I would love your two cents on my recent ACES workflow.

If you use project wide color management in Resolve set to ACEScct, all raw footage is automatically converted to the working space. If you do it manually, you can set the footage to directly decode to ACEScct yes. What do you mean with set IDT to no transform? In manual management directly decoding to ACEScct means you don’t need any IDT for that footage. You may want to double check if setting it via the Raw tab also takes into account the white point adaptation. Otherwise I’d do it via an ACES Transform node.

In the case of .mov files you’ll want to make sure that the encoding primaries and transfer function really match. Blackmagic has made a lot of camera encoding spaces across their released cameras. I think for the Pocket 6K it’s Blackmagic Design Film Gen5 but you may want to verify this.

Correct.

That would only be the case if the file was mis interpreted afterwards. If you export in ACEScg the file should also be read in Nuke as such. But ACES 2065-1 is the official ACES way for file interchange. Only CG renders in EXR tend to be ACEcg because that is the rendering space when ACES is used.

Yes. In Nuke the working space is ACEScg when choosing ACES (if not manually changed). When setting the IDT on the read node, the config converts that file from that to the working space.

Yea ACES 2065-1 is what it should be. In some studios it is mutually agreed up on always using ACEScg instead as long as it’s interchanged within their facility to avoid confusion between what was CG or an interchange file. This can be a choice but is not recommended by ACES standards. Always tracking which file is what is always important.

Yes both are linear. I probably butcher the explanation part as to why they exist so I’ll leave that to someone else if necessary :).

That is correct, as long as you are working on the same monitor you originally graded using. But often you might grade using a Rec.709 Output Transform on an external SDI monitor, but then do VFX in Nuke on an sRGB computer monitor. So you set the Output Transform for the current monitor.

Also if, for example, you are working in Nuke on an sRGB monitor, but want to render out a Rec.709 video deliverable, you would set the Output Transform to sRGB in Nuke while working, and Rec.709 in the Write node.

I think it’s to keep the longevity of ACES as a color management system in case displays down the line support a gamut wider than ACEScg or frankly any space currently available.