Log-Rec709 roundtrip in After Effects
I have been trying different workflows for a while, and have a few insights about this but would like to ask you folks How do you approach compositing LOG mixed with different sources of video with the intention of reverting to LOG composite at the end non-destructively?
simple setup: got a Log captured footage (Arri) and I want to composite on top of with with mixed elements from sRGB sources (Solid BG with gradient, Video captured sRGB/Rec709 etc) and at the end to export Log.
so far I tried different workflows and most of them did damage the video signal slightly even when in 32bits:
1. ICC profiles in After effects using color management: when using color management either through the interpret footage and render dialogs or through color profile converter – the signal does not look the same when completing the round trip. it’s a little clipped. this is not good.
2. Adjustment Guide Layer with LUT on top of everything and adjusting all my sRGB sources to look like LOG proved very unintuitive. imagine wanting a specific color in the background and have to color correct it under an adjustment LUT to make it look the way you want. and also color correct every sRGB footage from explosions to tv screens to have the LOG look… don’t like that yet this a common workflow
3. The ACES route: unfortunately I haven’t found a tutorial or a guide to show how to you complete the roundtrip back to LOG. all I have seen is how ACES gives you better color corrections and effects when placed in the sandwich of the Aces adjustments. but not way back to LOG country which I have seen
4. Invert LUT on sRGB media: the only workflow I found which is non-destructive for now is use an variation of #2 but instead of manually applying color corrections to the sRGB sources to look like LOG, I place on each of them an inverted LUT using OpenColorIO plugin (chose the Arri LUT, then hit Invert).
please those who have experience with this, share your thoughts and workflows 🙂 thanks