So the second roll I put through this camera came back blank. The first roll was reasonably successfull. This roll was shot using a different back and was Fuji Pro 400 film. I was also using off camera flash on this roll. I was triggering the flashes with a Yonguno YN622 on the hot shoe of the speed grip. I metered for the flashes with my Seconic flash meter and I was at about 1/160, f11 with the main flash on about 1/4 power if I remember correctly. I was using a 200mm lens, for the previous roll I used a 75mm. I did have some problems getting the yn622 trigger into the hot shoe and had to use a plastic spatula to push the pins up to get it into the hot shoe. Nevertheless the flashes were definately firing but the film was entirely blank, no film markings or anything. The lab said it looked like it hadn't been exposed. The only thing I can think of was that I must have loaded the film wrong but I don't remember noticing anything different from the previous roll. Anyone have any other ideas?