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ACES way to control how much the highlights gets compressed?

Posted: Tue Jul 12, 2022 12:52 pm
by MantasKava
Hello,

The topic name sums it up pretty well I think. But just to be sure:
In Redshift there's this option called "Allowed overexposure"
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That lets me control how much the highlights get suppressed.
Now the question is, how do I control this in Octane?

P.S. We're talking ACES workflow here

Re: ACES way to control how much the highlights gets compressed?

Posted: Wed Jul 13, 2022 7:03 am
by MantasKava
Wow, lots of valuable info on your website. Though I must admit it's a bit much for me to digest it all in one sitting.
I'm afraid we can quickly fall into this rabbit hole of color science, but I have many questions for a long time now, and you look like someone who could answer some of those to me. So let me ask:

1. Main reason (for me) for using/trying ACES is to get rid of constant clipping/overexposed/burned highlights, or not nice looking highlights in general (it's a problem when working with interiors, especially). There's an over-saturated highlights problem also. And ACES helps tremendously in this regard, no burned-out/clipped highlights anymore, I'd even say highlights get compressed too much. Which is another problem and that is the reason why I started this topic to begin with). Question- am I choosing the wrong solution for my problem?

2. If ACES is so "bad" for 99.9% of the users, why is such a major developer as Maxon/Redshift implementing it into their software as default? Hard to believe they are too stupid to know this stuff.

3. What file format/bit depth/color space should I use when exporting for PP in an external app (Fusion in this case) when using Filmic AgX or Filmic Blender?

4. Which one do I select here? If I want to export for PP in Fusion.
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5. Is this the right OCIO View option when using Blender Filmic? Every other option looks really wrong I found.
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6. What is this button for?
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Re: ACES way to control how much the highlights gets compressed?

Posted: Wed Jul 13, 2022 7:12 am
by MantasKava
Just for clarification:
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This is when NOT using ACES. How do I achieve this look without it? Pay attention to the highlights.

Re: ACES way to control how much the highlights gets compressed?

Posted: Wed Jul 13, 2022 3:31 pm
by MantasKava
Looks like this one is the original ("legacy") Filmic OCIO.
I would recommend to stick with AgX as it is a drastically improved version.
Do I understand correctly, that by "legacy" you mean Blender-Filmic one? that you mentioned in your blog as well.
And so AgX is newer/updated version of Blender-Filmic, correct?

Re: ACES way to control how much the highlights gets compressed?

Posted: Wed Jul 13, 2022 3:43 pm
by MantasKava
And just to confirm- I load up AgX OCIO, set the Camera Imager Ocio view to "sRGB:Appearance Punchy" and that's it, I am good to go? If I want to ditch ACES and try out this AgX thing that is
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Re: ACES way to control how much the highlights gets compressed?

Posted: Wed Jul 13, 2022 7:20 pm
by SSmolak
In my opinion ACES can completely ruin most of the exterior scenes with strong sunlight. Shadows and shadow areas are too dark. Reflection in windows are too much saturated and they have color hue issues. These issues can't be repaired even in post.

Re: ACES way to control how much the highlights gets compressed?

Posted: Wed Jul 13, 2022 9:29 pm
by SSmolak
elsksa wrote:
SSmolak wrote:These issues can't be repaired even in post.
They absolutely can. They just shouldn't be here in the first place.

To clarify: the issues are at the core, any "fix" is considered a workaround, the core issues will remain.
I had too much color shifting in reflections in dark areas where mid and bright areas had correct ones compared to non ACES version to make it good looking in Post Proccess. Most times there is too many work to make them good looking.

Also I see that AGX has broken or not production ready OCIO transform file because there is no way to restore AGX look from Octane in Affinity or Photoshop using OCIO plugin. Only way is to render it as 8bit.

Re: ACES way to control how much the highlights gets compressed?

Posted: Wed Jul 13, 2022 10:04 pm
by SSmolak
elsksa wrote: The reason it is happening (in Affinity Photo) is due to incompatible OCIO versioning. AgX requires OCIO v2 implementation. This edited version of AgX should work on Affinity Photo.
Thank you very much, works perfectly now in Affinity and Photoshop but reducing gamma by 2.2 ( Affinity ) or 0.45 ( Photoshop ) is needed after conversion.

Re: ACES way to control how much the highlights gets compressed?

Posted: Thu Jul 14, 2022 8:16 am
by MantasKava
The steps are as follow: an EXR 16-bit beauty (linear) export, plugged to an OCIO node in Fusion with AgX loaded and set to Input source: Linea BT.709 and Output source to sRGB:Appearance Punchy.
Ok, so when it comes to PP in Fusion (ACES way) steps go like this:
1. ACEScg > ACEScc (or ACEScct)
2. Step where you do all the PP
3. ACEScc > sRGB

And how about this AgX way? In which step/part should the PP happen?

Re: ACES way to control how much the highlights gets compressed?

Posted: Thu Jul 14, 2022 8:30 am
by SSmolak
I don't know about Fusion but ACES shouldn't be used in conversion if you use Agx. Just try conversion that it is included in OCIO AGX like Linear to AGX Srgb. It works fine in Affinity and Photoshop. Tomorrow I will include exactly conversion scheme.

I saw your past images - this can be done using Highlight Compensation in Camera Imager too.