Plusses: Easy to do, instant reset, extremely visual, really hard to figure out.
Minus: You
can't do it super-super close in extreme sunlight. But who does that anyway?
This is a new
trick. I have not seen a gimmick like this before. I had a guess as to how it was done and I was WAY
off. This is one of those effects that let's you perform what appears to be a 'camera trick' in real
life. The only frustrating part is that it's so good, I want to do it multiple times for people!
(Which, of course, wouldn't make any sense, so you can't.)