I don’t think I’m having the same problem. I definitely agree that something is wrong in whoville with blacks like that.
I’m digitizing 1:1 SDI into Avid from a BetaSP tape. So the quality should be as good as I can get. When I export to an Uncompressed quicktime 8bit, this is what I get:
This is what my blacks look like:

This is the interlacing that occurs:
