I'm having serious trouble with light flicker, and I'm not exactly sure why.  I've done all of the obvious things, like wearing black, blocking out natural light, using lamps, etc.  I also always try move my arms away from the camera when I take a picture (the camera has a one-second delay).  Yet despite my best efforts, I still get very bad flickering.  Is there anything I could still do to stop this?  Thanks!