This is something I would normally try and figure out on my own, but I'm at work and don't have any of my equipment here to do trial and error. When using flash, what needs to be done to dial down on the ambient light? I was looking through strobist and one of the posts was about a street photographer who uses a snoot to shoot. He shoots during the day, yet his pictures come out as though it was darker out. Is it aperture number that dictates ambient light? so bigger aperture, lower ambient light? if that's the case, how do you compensate for flash?