Okay, here's what doing a bit of digging has found:
1. The effect I'm seeing on these wine glasses is very similar to the retroreflective properties of a cat's eye.
Article on Retroreflectors:
http://en.wikipedia.org/wiki/Retroreflector
Image of Cat's eye acting as retroreflector...
I believe the girl behind her should have her hand behind the glass. However, that still leaves us with the question as to why a distant hand that is not completely covering the area behind the glass would allow the glass to fully illuminate, when a hand that's directly behind the glass does...
Just thought I'd mention something that I noticed in a single image, there's one where it's not a hand that's positioned directly behind the glass, but rather a black (presumably) leather purse, with only a few studs that could possibly reflect any light at all, the hand is located well down the...
Hey all,
I went to my 10 year HS reunion party last night, and took about 125 photos using my Sony Alpha 350DSLR, a kit lens, and a Promaster hot-shoe flash. The camera was set to manual exposure of 1/10th sec to allow the ambient light to fill in the background, while the flash was left on...