ACES and AOVs - wrong tonemapping?

[KeeWe]

Hi guys,

I'm currently working on a project where I only need the Diffuse Filter and some other AOVs and I discovered the following:

When working in ACES 2065-1, the Diffuse Filter doesn't match what I see in the LV, it needs a massive gamma correction. This seems to be scene related because I tested the same settings with another scene (completely different lighting scenario) and the Diff F was just slightly off. The main beauty layer looks perfect. My setup:

- ACES checked in camera imager
- EXR octane, ZIP compression
- Float 32 / ACES2065-1

Same settings in AE.

Cryptomattes seem to be affected as well, white isn't pure whit (though I guess this has another reason).

Again, the main beauty fits perfectly without any correction.

Please see the attached images.
1) Gamma correction from 1 to 1.55
2) what the LV shows
3) what AE shows right after import

Adjustig the Gamma is not a big deal right now, but a) it would be nice to rely on the LV to get what you see and b) it seems the gamma correction is scene dependent.

Am I doing something wrong or ist it an unwanted behaviour of Octane?

Thanks in advance.

[elsksa]

Compositing AOVs elements ("passes") is entirely done "in-linear", universally.
ACES ODT is added somewhere after in the chain. There isn't a single "per AOV "gamma" correction" to be done, and shouldn't be (as incorrect).

AE as the compositing software is unreliable. Actual compositing software are not only designed but more reliable and suited for compositing and proper color pipeline/workflow. Typically Nuke or Fusion. A life changer for AE users.

[KeeWe]

Ok, but what would be the solution? Switching software: not an option right now.
Beside changing the gamma inside AE, is there a way to get the exact same result as in the LV?

[elsksa]

The solution is in my first phrase: by ensuring the compositing is "done in-linear" (without any form of color correction/operation/processing) during it, and applying the ACES ODT (supposedly sRGB - Output) only at the end. As it should be in any compositing software.

Question is if AE has a proper OCIO implementation/support and color management that would allow all of that, which this software isn't known for having (as not originally purposed for such critical compositing tasks).

[Aleksei]

I feel your pain, KeeWe.
There is no easy and understandable explanation on the internet how to "play" with the OCIO profiles. I mean easy and understandable for an artist, but not a techincian.

Long story short, make sure that you have set the OCIO profile in the AE in project settings (screenshot below). The config.ocio file must be downloaded from Github (check this tutorial if you don't have that file).

Here:

1) here you link your ocio config file from Github.
2) This field may be different in your case. Because it must be similar to what you set in Octane renderer. In my case it was "Output - sRGB". Make sure to check the "Show All" checkbox next to the dropdown menu to see all the options.
3) I guessed this result. I assume this must be corresponent to you current scene ot monitor profile, which is sRGB in my case.

I hope this will help in your case, because I'm not sure
There is no fundamental knowledge about all these relations between profiles. All this is a result of trial and error.

[henningricke]

I strongly recommend having a look at Raphael's (aka Silverwing) Tutorial on ACES and After Effects!

https://www.youtube.com/watch?v=6MdhaWtpI5o

Everything you need to know is in there.
Unfortunately ACES only looks correctly in 32 Mode in AE, wich generally is a broken mess. (Yeeey Adobe! )
... But it works in principle.

[KeeWe]

Sorry for the late reply.

@Aleksei and henningricke
Thanks for the manual and suggestions, but that's not the problem. ACES works just fine when working with the beauty pass (I followd Raphael's tutorial). It looks the same in AE as in C4D. The problem is, that the passes seems to get altered with when rendering. I know I actually don't need ACES when using only the diffuse filter pass, but I don't think it is correct that it looks right in the octane LV but needs a gamma correction in After effects.

Maybe Ahmet can comment on this?