Might have to do some intense 4-5 seconds of roto. Hands pulling weeds in a mulch bed. Need to cut out the arms/hands and lose the mulch bed background. I can animate masks in AE or Motion, but is there something better? Most roto I usually do is a simple animated mask cutting out objects and such for a transition. Not fingers and hands! The footage is 4k C300 MXF.
You could try using the chromakeyer in combination with the color board to key out the mulch, or, it may be easier to generate a key on the hands/flesh tone, then make an intermediate mask or "hold-out matte" from that. Still finicky, but in a different way from roto.
Something that's not always very intuitive is that you can deliberately push exposure, contrast, saturation, etc. in the color board to make a shot that looks horrible but keys really well. You can always restore the color changes later, after having extracted the hold-out matte. Also, you can invoke as many instances of the keyer and drawn mask as you need.
Thanks for the suggestions. All good ideas. Unfortunately tried 'em. Apparently there's a real good reason Hollywood hasn't accepted brown screen chroma keying as a standard practice. Just not enough luma or chroma to deviate from skin, clothing, shadows and so on. We are editing around the issue. Or reshoot.