This is a feature (multiple exposure) built into the Canon 6D that I picked up about a month back. You can capture from 2 to 9 exposures in a shot. I went as high as 6 and for the candle it didn't improve the interesting level. As far as in camera you frame your shot for one image, shoot re frame for the 2nd shot and shoot again and viola after 5 or 6 seconds you have your final image.
I also spent some time shooting 3 candles and it was nice but I still liked 2 the best and it made for a more interesting title IMO. I will explore this feature more in the near future. I've noticed that EXIF data is missing from all my shots with the 6D after I convert so I'm assuming I may have a setting wrong in Canon's DPP, I'll have to take a look and see. Paul
I removed Sissy's hand entry since it got a subtle nudge even tho I suggested in my comments that it was the frosted glass I was focusing on. Her hand was only part of the overall image. None the less I'm always experimenting and trying to break the rules. Paul
Hummmm..I need to explore this....but I will say that I very much liked the Hand of Child image....maybe a little off topic, but robustly pink she was....great image in its own way. Traveller