I think this is a pretty good idea, but it was quite difficult (not in a good way) due to field-of-view issues (canvas was a little too far apart from the people). As I couldn't focus on the people and the canvas at the same time, it made it less tense because I didn't realize I was already having problems until it was too late to fix them. It might be better to see the people out of the corner of your eye at the same time.