Color Management with Log-C textures?

[Anonymous]

I have an interesting Color Management situation that I'm trying to figure out the best workflow for.

We are creating a Times Square style jumbotron wall on some buildings. The plate photography is all in Arri Log-C. Most of the plates that will be placed into the giant TV screens are also in Log-C. Ultimately we'll want to be delivering a composited shot that is in Log-C so that it is within the same color space as the rest of the piece when it goes to Color Grade.

Is there some sort of a Color Management workflow that will allow me to tell Arnold in C4D that some textures are Log-C, while others are sRGB (like news logos and other graphical elements), and have the EXR Render itself be rendered as Log-C? That way it's in the same color space as the Plate when we're doing the compositing?

I know this is all much more complicated than it needs to be, and by having the Plates graded before the VFX it would solve a lot of these hurdles, but the Post company is wanting to iron out a consistent workflow for such projects as these so that the grade can always be done as the last step.

Any help or insight is greatly appreciated!

[ashley.handscomb.retallack]

The usual practice is to convert the colorspace for all textures to a linear (or ACEScg) colourspace so the CG render is all in linear. Then the CG elements a recombined in compositing where the plates are also converted to linear, before final output back as LOG-C.

If you get an ocio config with logc in it you can use that with maketx or the Asset/Tx Manager in C4DtoA. For example, you can get the default OCIO configs from http://github.com/imageworks/OpenColorIO-Configs/zipball/master inside here is the nuke-default configs that contains AlexaV3LogC then add the flags

--colorconfig /path/to/nuke-default/config.ocio --colorconvert AlexaV3LogC Linear