Zorki 3 shutter capping

[comp_wiz101]

Hello all. Anyone know what can cause shutter capping at the beginning of the run across the frame? i.e. The shutter starts out closed and slowly widens to the correct size. It is an intermittent problem.

 

[pvdhaar]

I would think that capping at the end of the exposure is more likely as the second curtain overtakes the first one which slows down. Capping at the start of the exposure would require the first curtain to first stick and then to accelerate faster than the already running second one. If you deduce the problem from the prints, have you factored in that the image is formed laterally reversed?

 

[comp_wiz101]

Yes, the capping is starting at the beginning of the run. I have recently cleaned & lubed the camera, so it is my belief that someone has not tightened the curtains properly. So, last night I loosened the pressure on the second curtain to find that it was wound up 5 or six times! I wound it three turns and it is working much better now. As per the Fed & Zorki survival site, I readjusted for a snappy front curtain and a slightly slower second curtain. I still need to fine tune and set it against another calibrated shutter, but I think I might have the problem solved

 

[comp_wiz101]

PS: Yes, I realize that this seems contradictory.

 

[Kim Coxon]

Not really. The most likely scenario is that the second curtain was getting slow because it was gummed up. Instead of treating the cause, someone hid it by over tensioning the second curtain and inducing a second fault. You cured the first problem so the over tensioning became apparent and have now dealt with that.

Unfortunately, there is a lot of false advice on the net which says the best way the cure a slow curtain is increased shutter tension when the usual cause is dirt/muck requiring a CLA.

Kim

PS: Yes, I realize that this seems contradictory.

 

[comp_wiz101]

Thanks Kim. I thought it was odd just because I had thought that, if the second curtain was too strong, that it would catch up later in the frame instead of earlier.
Also, it's easier to wind now 🙂