I am a large format photographer who rarely deals with flash. In-studio, I use continuous lighting. Now I plan on using a vivitar 285hv flash off-camera with a Canon F1 (new) and a Mamiya 7ii and perhaps a handheld 4x5 life a SuperSpeed -- and I have no idea what to do. I do have a Sekonic flashmeter though. So can someone give me a quick run down, for example for a portrait outdoors espcially involving fill light? Not quite sure how to "balance" the ambient v. flash exposure, and whether this is necessary. I understand that the synch speed on the canon f1 is 1/90 -- so I have to use shutter speeds that are slower or equal to that. The other cameras of course don't have focal shutters so not an issue there. So suppose I want to take a photo of a backlit subject. The ambient exposure is ASA 400, 125 at f/16. I am guessing I put the vivitar on full-power manual mode, flashmeter the shadow, and end up with another exposure setting. Then what? I'd buy a book but they seem to all deal mostly with TTL flash and digital cameras. Recommendations? And please do not refer me to strobist -- been there.