Off-camera flash for Canon F1? I own an old Canon F1 and have been wanting to try out a flash unit. Looking into the shoe mount adapters that exist for the F1, I’m not sure I’d like to have the flash mounted to the camera, as it’s already heavy enough as is. If I wanted to use a flash unit like the Vivitar 283 off-camera, would that be a possibility? I know the 283 uses a sy…