posted on Dec, 14 2007 @ 10:35 AM
answered your question. Sorry with the Holiday rush I've not had a ton of time lately.
The blocking is seen a lot, but is not a clear sign of anything other then typical artifacts of jpg compression or averaging.
I've seen some fakes that show light blocking, but what gives them away more is differences in pixels between the composited object and the
background, and that hearkens back to me looking at film grain in negatives. Not exact, but similar in the idea.