I took the photo below using a D70 with mounted SB800. I put the diffusion cap on top of the flash and pointed the bulb nearly straight up at a fairly low hanging white ceiling. I was surprised to still see strong shadowing behind the subjects. I had a bit more success when the subjects moved further away from the backdrop; however, I am wondering if my error was either placing the subjects too close to the wall or selecting an environment with a low hanging ceiling. Would the picture have been better if the ceiling was higher or should I never ever place subjects that close to the backdrop no matter what type of ceiling I'm bouncing the flash off of?