I was wondering if it's possible to use an f lens on a 500 c/m body. I have a body synch on my early c/m so it can work for flash or if I train myself to be accurate with the rear shutter by hand squeezing the time. I experimented by taking my CF lenses and putting them in F mode--and also trying in "B" shutter mode. Results: the f mode functioned correctly (stopped down for the exposure) BUT the lens resets back to wide open before the back shutter is allowed to close. the b mode worked just fine. NOW--is this the proper function of F lenses or an artifact of the f mode on the cf lenses--in other words--if I put a REAL f-only lens on the body, will the aperture still reset before the rear shutter closes? this is not really an issue for strobe work but if you're timing with smaller apertures, it is..... anybody have an f lens that they can throw on a 500 body and see what it does when stopped down?