Well, it seems that my Bronica has developed a problem on the second roll of film I have shot with it. Basically, I have been shooting using mirror lock up and a cable release. So winding the crank until the shutter is cocked, pushing the mirror lock up switch to S and then pressing the cable release. Halfway through the film though it refused to fire - instead the red light showed up in the viewfinder if I pressed the cable release or shutter button. Oddly though, it then allowed me to advance to the next frame, so I presume I will have blank exposures. It seems to work fine at home now without a film in multiple exposure mode. Has anybody got any idea what the problem is? 
