It's hard to do! I just use the flash on the camera, the tank light and a lamp nearby I can aim at the tank, or a variation of the three. The Pleco sits still a lot so he's easy to get. The Angels are more difficult but if I time it right it's not bad. The larger sizes give a lot to focus on. When I had Tiger Barbs it was near impossible unless they were sleeping. They sleep nose down, sometimes almost vertical. Yeah, I can't argue with that. I got a great deal on mine though.