only guess I can make in this case is bad keying/qualification combined with noisy, compressed footage.
not enough info, and no example to see.
I asked about monitoring, since once you see something properly on ext monitor (preferably pixel to pixel) then you have much less surprises on exports.
it is not uncommon to notice noisier keys after export then go back and fix them.
maybe you can show/explain one example, preferably this way:
1. what kind of footage you used - still or (better) few frames of original ungraded footage
2. what tools you applied in your nodes
3. still or (better) few frames of export
It is important that you offer more details when you are looking for help because there are a lot of variables at play. it could be hardware, it could be specific combinations of software or it could be...?
What Mac Pro are you using, what OS, what is your graphics card and how much RAM is installed ? I've had numerous problems rendering on the 2013 Mac Pro with 12 cores 32 gb RAM and dual AMD D700 graphics cards. The problem was more pronounced before Yosemite and with older versions of Resolve. The dual AMD 700 cards are not up to the task of 4K in Resolve. Some people have had better luck with the D500 gpus. Are you on at least Yosemite and the latest version of Resolve?
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