Hi all, I've bought a pair 1600W external flash units. I'm having trouble trying to get them to flash in time with my canon 1000d built in flash. When I take a photo they do flash but don't seem to make any difference. I have to use the built in slave sensors (triggered by the built-in flash) as I don't have a hot shoe flash. I've tried playing around with shutter times etc but they are still not hitting the mark. Anyone got any ideas on what I should be doing here.