I thought my shutter was going on my Sony A100. I was trying to test my wireless flash when I set the speed at 200 the bottom 1/4 of the frame was black. Then when I increased the speed to 250 half the frame was black. When I set the speed to 320 3/4 of the fram was black. I removed the flash transmitter and tested it and it was working fine. I am going to test the camera outside tomorrow.