[Jacob Brown]"In every export I have done, there is severe banding wherever a transition is. At the beginning of the film, a fade from white transition bands badly on top of a grey background.
FCP sees the ProRes video as 10bit, what ever app you are viewing the file in is only seeing the 8bit ( like the QT player on either platform)
TURN OFF any realtime processing- all of that in FCP or avid is only 8bit, set FCP to Safe and render the file out to see if it is still there.
You don't say what you are playing on or how you are viewing the file, best guest here is that you are not working within the SMPTE spec (density locked btw 16-235) so your whites are too high and your blacks to low to start.
An easy fix is to process the clips with a bit of noise, 1%-3% is usually enough to clean the image contours.
Post and Production Workflow Consultant
Production and Post Stereographer