I've been given some green screen shot with a 5DmkIII. Hand reaching across to the back of a TV with prominent shadow: 20 ire to about 15 ire where the shadows are. Seems like it was shot with higher motion blur than I am used to like they used 1/30th instead of 1/60th for a 30fps setting. Of course, lots of noise because it is so dark (don't know what ISO it was shot with).
Anyone ever gotten a good key with these light levels using this sort of camera? I'm having a horrible time and just want to jettison the whole thing.