OT: Stuck shutter/mirror?

[sooner]

Please indulge me a non-rangefinder technical question. I got a Rollei SL35M that checked out great upon arrival, but with film loaded it started to stick. I pressed the shutter button and the mirror would just stay up, overexposing the shot, as if it were stuck. We're talking 1-3 seconds here. The shutter speeds seemed slow, also. But upon taking the film out again, I couldn't get it to repeat the failure.

I checked the blades and they seem fine, no oil or anything unusual, and they stop down nicely. Any ideas on what might be causing this? I'm using a 55mm f1.4 lens. Any advice appreciated. -John

 

[Kim Coxon]

Hi,
This one does seem a little odd in that it is only slow with film in. As a general rule, the whole cycle in an SLR works like a set of dominoes falling over. Each stage triggers the next. When you press shutter release, the mirror swings up. This releases the first curtain and the timer releases the second curtain. Once this is complete it allows the mirror to fall and unlocks the wind mech.

I am not overly familiar with the Rolleis, hopefully it has a mirror lock up device. If so try this. Take the lens off, lock the mirror up and fire the camera at a slowish speed and watch the curtains. Once you have an idea of the speed, repeat the process with a "dead" film in the camera. If the curtains are slow to move, my best guess would be that the film is somehow rubbing the curtain. If this is the case you will need to look at any buckling on the curtains or perhaps a fault with the pressure plate. If there is no difference then there is a problem elsewhere perhaps in the mirror linkage. But I wouldn't think that this is the case as the mirror is tripped by the shutter but not linked to it.

Hope this helps
Kim

 

[sooner]

Thanks, Kim. I'll follow your advice and make those tests. I will also develop the test roll tomorrow in my dark room photography class. Regards, John.