Color Management

[jimho]

Recently there is a major contraversy on Color Management between me and someone from Otoy,
As mentioned in a post I am quite confidence on this issue, and seems for a long time there are quite some people keep looking for a solutions for this issue,
So I guess maybe my knowledge could help some people, and probably this also help Otoy to get this issue properly resolved,
To let more people to be involved,I guess we can concentrate this topic here,so I initiate this one.
As well since it is contraversy, though I think I am right, but finally it might my mistake(though I do not believe so), it will be also good,if this can help me to fix it.

Here is the post that I shared my major opinions on the color management issues,
viewtopic.php?f=24&t=75728&start=50#p389673
if color management is also your confusion and struggling with it,read the above post and also we can discuss here,
Maybe some people do not realize what they face is a color management issue,
for example, when you get a rendering in octane, after you save it, then you want to edit it in other software or windows viewer, the image get looking different, too dark or maybe to bright,
That's it.

[jimho]

viewtopic.php?f=9&t=75008&p=389816#p389816

[jimho]

Spent some time on ACES/OCIO/EXR etc.
Found some resource to list here:

• 1. the best EXR plugin for photoshop
  
  EXR-IO:https://www.exr-io.com/
  
  2.to download the latest OCIO-configs here, ACES 1.2:
  
  https://github.com/colour-science/OpenColorIO-Configs
  
  3. OCIO for photoshop
  http://fnordware.blogspot.com/2017/02/o ... oshop.html

It seems only v2 of ACES/OCIO can support monitor icc(will come out the next year), so generally ACES/OCIO still not yet surpass what Adobe icc can do(many years ago), just a take look into...

[jimho]

still color management
viewtopic.php?f=33&t=75856#p389965

[jimho]

A good website on ICCs
https://ninedegreesbelow.com/photograph ... files.html

to download here:
https://github.com/ellelstone/elles_icc_profiles

for example an ACES image(exported by octain render 2020.1.XB2)can be well recognized by using ACES-elle-V2-g22.icc

1:Aces2065-1,
2:assigned "ACES-elle-V2-g22.icc", which will look same as the "linear" export
3:adjust the gamma to 2.2 (which is lost when otoy export the image, that makes the image far different to what it should be.)
4:original looking from Octane render's viewport(for compare)

[karl]

For Elle Stone's ICC profiles you should be using ACES-elle-V2-g10.icc, which has no gamma (i.e. linear). Then you will no longer need to use step 3 to unapply the gamma transform. In general for any EXR file only the g10 files should be used, because all EXR files are linear.

So then the steps are: export EXR in ACES2065-1 from Octane, load in Photoshop, assign any ACES2605-1 ICC profile (e.g. ACES-elle-V2-g10.icc).

[jimho]

Yes in theory it should be the g10 profile,I did do that
but they are exactly the same appearance, I am actually quite curious why.

[jimho]

you may try it by yourself,

[jimho]

the Gamma 2.2 is coming from the octane render's camera imager node,gamma is set to 2.2,which default number is 1.0

[jimho]

OCIO WORK FLOW2
As mentioned here, there is some tools for OCIO

• to download the latest OCIO-configs here, ACES 1.2:
  
  https://github.com/colour-science/OpenColorIO-Configs
• OCIO for photoshop
  http://fnordware.blogspot.com/2017/02/o ... oshop.html

Using the OCIO plugin for photoshop to converting OCIO image to sRGB

1:Aces2065-1,exported from Octane Render 2020.2 XB2
2:from the ps filter find the OpenColorIO,within the plugin UI indicate the OCIO configuration which is downloaded from the above ACES1.2,then choose convert from ACES2065-1 to output sRGB
3:the result of "output sRGB"

The comparison of results,

1:the icc workflow result: assigned "ACES-elle-V2-g22.icc",
2:OCIO plugin convert result
3:assigned "ACES-elle-V2-g22.icc"+ manually adjust gamma to 2.2, as mentioned the gamma is based on imgae node
4:Octane Render 2020.2 XB2 Viewport effect

Obviously, the OCIO relys on the work flow the result is not consistancy.
This is the reason I mention the Adobe icc solution is more reliable.