ACES way to control how much the highlights gets compressed?

[SSmolak]

elsksa, you have huge amount of knowledge. But this knowledge is only knowledge. I tried and lost huge amount of months to test some things. Colors, Aces, OCIO. All of the things as you said is only theory. Every scene is different and trust me - I had scenes that looks totally wrong using ACES. Of course you can repair everything - but why to repair ? Final render should looks as good as possible.

Most of the OCIO going to compress highlights by different way and also brighten or darken shadows ( for example Blender contrast filters ) - all of this can be done simple in Photoshop Camera Image using 16bit rendered image. Only good way to use these OCIO in Octane is that you have real live view of what final image will looks. Of course there are different gamma changes in RGB but all of this can be done using simple LUTs in Octane.

There is no any difference using standard Luts in Octane Camera Imager than using OCIO or ACES in final image. Maybe 5% of people can find any difference.

[SSmolak]

I'm not only who see ACES problems :

https://www.facebook.com/groups/OctaneR ... 5034964229

ACES produce low-dark areas very dark in Octane LV. Working with ACES cause to make post processing. If you want proper view in LV you must rewrite all materials.

[jobigoud]

I feel something that is missing is a list of the most common workflows and their advantages and drawbacks. Including the workflows considered wrong.

For example one common workflow is to save as non-linear sRGB to 8-bit PNG and apply further color and contrast adjustments manually in Photoshop before exporting to JPG.
Although it's "wrong" and loses a lot of data it's very common and the shortcomings should be documented.

Another workflow is the same but with a Response curve or LUT applied directly in Octane. The limitations of doing this should be clearly outlined somewhere. The advantage of this approach is you can work on the scene with something that is close to the final look and limit external post processing. Assuming the result doesn't need to be composited with something else.

Another typical workflow is to save to linear sRGB as 16-bit EXR and do color grading somewhere else.
Same for OCIO-based workflows.

Not everyone has Nuke or a dedicated colorist and many scenes aren't going to be composited with anything else in which case the output of Octane is close to the end of the pipeline.

[elsksa]

HDRI created by Jorgen Herland

A fella I know for years. He has been producing my favorite HDRIs with continuous improvement since the beginning. Great choice.

white cube isn't white at all.

It surely is white.
White ≠ pure RGB emission aka "1, 1, 1" or "255". Particularly in such conditions.

Worth mentioning:
• There is a known HDRI limitation in Octane ("clamped"). It has been reported in the past.
• Filmic ("Legacy" or AgX) compresses the "scene referred linear radiometric values" down to the display "output referred" range, and does so similarly to log-encoding in cinema cameras that many in the motion-picture industry, are familiar with for years. Unlike in "CGI" where "straight sRGB" inappropriate conformation was wrongly as-default for decades. Too many people got used to that atrocious broken RGB imagery.
• There are many aspects involved and to consider, psychophysical included, e.g. perception lightness phenomenon, the "Benary Effect", and some more.

For more information, there will be pages about it on my website, which is also much more practical to write or read than socials/forums.

[elsksa]

elsksa, you have huge amount of knowledge. But this knowledge is only knowledge. I tried and lost huge amount of months to test some things. Colors, Aces, OCIO. All of the things as you said is only theory. Every scene is different and trust me - I had scenes that looks totally wrong using ACES. Of course you can repair everything - but why to repair ? Final render should looks as good as possible.

I've been working for years in CGI/VFX, Post, Photography & motion picture digital production. This isn't theoretical. I don't know what you thought about me, but I'm in the field for years.

Feel free to believe anyone unqualified.

Most of the OCIO going to compress highlights by different way and also brighten or darken shadows ( for example Blender contrast filters ) - all of this can be done simple in Photoshop Camera Image using 16bit rendered image. Only good way to use these OCIO in Octane is that you have real live view of what final image will looks. Of course there are different gamma changes in RGB but all of this can be done using simple LUTs in Octane.

There is no any difference using standard Luts in Octane Camera Imager than using OCIO or ACES in final image. Maybe 5% of people can find any difference.

You do not realize how all of this is wrong and misinforming.
Feel free to consult the previous replies, because I will only repeat what has already been written.

[elsksa]

Although it's "wrong" and loses a lot of data it's very common and the shortcomings should be documented.

Question is rather how it ended up being "very common" while it should have never. This is mostly due to unaware and unqualified folks misinforming to others. Hence why, a usually solid reference to follow is in feature film productions and VFX studios. Roughly the same can be done as an individual scale, just simpler with a simplified workflow/pipeline (made easy also thanks to software development being overall user-friendly). In fact(not addressed to jobigoud), many of high-end productions progress is being pushed to the lower spectrum of the industry: at freelancer/individual scale.

There is no reasons to follow improper workflows/pipelines. It's irrational and will break. Anyone who cares about the work, should not neglect it. It's not more costly nor more time-consuming when all of it is properly setup.

Another workflow is the same but with a Response curve or LUT applied directly in Octane. The limitations of doing this should be clearly outlined somewhere. The advantage of this approach is you can work on the scene with something that is close to the final look and limit external post processing. Assuming the result doesn't need to be composited with something else.

Many are near clueless of what a LUT is and do, how one is properly generated, etc.
Unlike what most think, a LUT is limited, even in high end productions, its usage is bounded to specific cases and a LUT is never the back bone of a color pipeline. Don't get me wrong, the LUT support in Octane is highly welcomed, as long as a proper LUT workflow is set. Properly creating a LUT can be complex, even for experienced feature film colorists, which are sometimes helped by some rare PhD-scientists on some high-budget productions.

Another typical workflow is to save to linear sRGB as 16-bit EXR and do color grading somewhere else.
Same for OCIO-based workflows.

That's currently the only proper "linear based" and "non-destructive" way. The post-work isn't necessarily "grading", it can simply be a proper conforming of the EXR light-data to a properly formed-image, which is well handled with Filmic OCIO, more specifically, AgX, recently. Grading is a term to take with a grain of salt in this context. I am referring to the actual color-grading work of a professional colorist, which vastly differ from "post-work conforming".

Not everyone has Nuke or a dedicated colorist and many scenes aren't going to be composited with anything else in which case the output of Octane is close to the end of the pipeline.

Blender Compositor is free and supports OCIO. Natron as well.
Beauty rendering is absolutely viable and I am in favor of it whenever it is possible (when compositing (AOVs, LPEs) are not requested/necessary).
I'm actually asking people why they export AOVs, many of them do it for no reason but because they saw others doing it. "Beauty rendering" (no AOVs or LPEs) can largely suffice in many cases.

Fusion is free but inside Resolve, I have a strongly biased opinion on this: DaFusion (Fusion inside DaVinci) can lead to more user-error due to the software "blended together" and confusing people because of it.
On that matter, many tend to think that DaVinci will give them the "Hollywood Look" which is also fallacious. "Grading" can be done with a few nodes (even just one ASC-CDL) in a compositing software.

I personally rather recommend Fusion Standalone which is around $300.

[elsksa]

I'm not only who see ACES problems :

Fabio_ACES.jpg

https://www.facebook.com/groups/OctaneR ... 5034964229

ACES produce low-dark areas very dark in Octane LV. Working with ACES cause to make post processing. If you want proper view in LV you must rewrite all materials.

That's not a "problem" per se. ACES has "problems" but that aspect is rather extraneous.
I know Fabio, and I also know he is not a digital imaging technician, colorist of color physicist/scientist. Take what he writes with a grain of salt.

I will repeat myself again and again, 32-bit is already excessive. 16-bit is more than enough.

ACES is certainly subjective in its "rendition".
The sRGB (or "Rec.709") ODT is known to be "more contrasty". ACES "system tone scale" (RRT+ODT) has non-arbitrary values. However, that look can be altered in an ACES compliant color pipeline, which is beyond the capability of most individuals. ACES isn't suitable for an individual, despite it's trendy popularity, but that's an other subject.

The RRT has been designed for a theatrical context aka cinema in dark environment. The same applies for most image makers: a proper viewing environment is necessary when working on digital imaging. Also a reason why post finishing studios have to follow a strict viewing protocol defined by SMPTE standards and recommendations for reference viewing environment conditions.

As mentioned in this forum thread, viewing conditions should not be neglected.
For instance, an inappropriate monitor technology, inappropriate monitor settings, non-calibrated monitors, and last but not least, inappropriate viewing conditions, should all be taken into consideration.

[elsksa]

By the way, it's admirable to see such interest here. It means something. Never stop being curious.

[SSmolak]

Orginal :

ACES :

Camera Responses, Lut's, Exposure, Gamma, White Point magic all inside Octane :

ACES :

Magic in Octane :

Response_Lut.zip

(642.31 KiB) Downloaded 113 times

[SSmolak]

Aces simulation with Camera Response + Lut :

Agfacolor_Optima_II_200CD_Zed_to_Aces.zip

(277.33 KiB) Downloaded 98 times

Left -> Camera Imager, Right -> ACES

Near 98% the same blue and green tint using Teigen28 cube but different settings :