[Andrew Kaytor]

I noticed the same problem, thought it was DV artifact, started shooting Beta and ingesting 8bit, same problem. Here’s my fix. Set up key with Keylight viewing Final Results and just ignore the noise for now. When you got the key set up how you want it, duplicate that layer, put it on top, change Keylight settings to: View> Intermediate Result, Screen Shrink about -7 and Screen Softness about 5. Finally change the blend mode of that layer to Lumonosity. Doing this should clean up any noise generated by blacks.

Andrew