Help - ocio (open color io) for post processing ?

Anim

I like to export exr canvases from Studio to post process them in Affinity Photo.

Does anybody maybe have some tips to share how to best do this?

Especially:

- Which ocio profile to use (I assume ACEScg might fit to what iray outputs, but I am not sure. I tried input = scene linear, output = sRGB)

- Setting the blend modes in Affinity (e.g. add or multiply)

I tried a few things but did not get a usable starting point so far.

Zicon

I often render each light source as a canvas and composite them in Affinity Photo. I load up the EXR files as a stack, ungroup the stack and blend the layers using Add. Then I add a black layer to the bottom, and an Exposure adjustment layer to the top. I set the value of the Exposure layer to the negative of the exposure value used for the render, so if the exposure value in DS is set to 13, I set the Exposure adjustment layer to -13. Then I have a composite that looks the same as a beauty render from DS, and I'm all ready to start tweaking.

Never had a reason to change profiles, so I just use whatever is the default when loading images to a stack.

Richard Haseltine

As long as you turn off the correction in Render Settings I think linear should be right.

Anim

You mean Tone Mapping, right?

My assumpion was that the canvas exr export anyway ignores that. Is that assumption wrong?

 

Anim

@ziconin

Thanks, I came to the same conclusion. OCIO conversions using "scene linear in" and "sRGB out" do not give a usable result in my test so far. So, like always, more trial and error.

 

Sevrin

Here you go.  I've been using these macros a lot recently. 

NB: They're intended for 32-bit renders, and look pretty bad on 8-bit images.

Anim

Thanks !  :-)

Anim

Got it with OCIO.

I assumed the profiles include a tone mapping. That was wrong. The prime exposure adjustment needs to be done before OCIO layers.