I am making this because I have seen no other reliable topics here other than this on Filmic Blender (Filmic) and Natron.
DISCLAIMER: I am by no means an expert. This is just the method that seems to work for me. Also note that this is only necessary for .exr files because they output in Linear ,not sRGB, color space. Because this is linear, it will work with any linear color workspace, but it should be noted that it is easier to work with the below settings than anything else.
TLDR: Work in linear and you should be relatively fine regardless of Color Management settings. Some things may look weird without tweaks though.
Install Filmic to (C:\Program Files\INRIA\Natron-version\Resources\OpenColorIO-Configs\blender). Just copy and paste the contents of Blender's color management folder.
Set Blender as color space. Under Edit -> Preferences -> Color Management.
Read the .exr
- Blender .exr files are unpremultiplied by default and should be checked as such on the read node
Do all compositing to the passes and merge them together again
Apply the OCIOLookTranform node with the prefered contrast under its "Look" dropdown
Apply the OCIODisplay node with gain set to ".10" (value could be variable, I've tested with multiple different .exr and .1 seems to be the average best)
If anything looks weird at this point, check that the input and output formats line up (they should by default, but you never know) and check that the OCIODisplay node view transforms to sRGB EOTF.
Should look like this (ignore Judy):
- Dark Blue: Main .exr Read
- Orange: Diffuse
- Yellow: Glossy
- Green: Transmission
- Gray: Alpha (I prefer to have a clean alpha on the side that I can work with)
- Light Blue: Subsurface Scattering
- Pink: OCIO nodes
If I have made any mistakes, misconceptions, or general screw-ups fell free to mention it in the comments.
Thanks for readin'
Edit 1: Applying the two OCIO nodes before compositing changes absolutely nothing. They should be applied after all edits are made to the render, but before any other composites are layered on top. I have fixed it above and have replaced the image to better illustrate this.