...so I just did the light shining in the curtain test and it turned out negative. I put it up to a lightbulb for about 30 seconds each time. I'll do another test with more time because what I'm noticing is that the shots that it shows up on are times when I was carrying around my camera for about 15 minutes in between photos. If this turns out negative, I'm going to just shoot with my camera in a black bag. haha.