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Message |
    
paul
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, July 08, 2005 - 09:39 am: | 
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i recently acquired a voigtlander vito b in very good condition.
after the first half roll of film however, the shutter release wasn´t, well, releasing the shutter, and it became apparent that the shutter was opening at the end of the film wind.
i checked the mechanism inside, and it appears that (i´m afraid my lack of technical part description may let me down here) the cocking mechanism doesn´t lock and cock the shutter release, but follows all the way through and releases the shutter in the process.
does anybody have any ideas on this one?
it´s a great little camera and i´d love to get it going again.
paul |
Winfried
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, July 08, 2005 - 01:36 pm: |
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I don't think it's a problem with the film wind/cocking mechanism. My best guess would be that the cocking shaft of the shutter is not latched by the internal shutter release mechanism inside the shutter. |
Stuart Willis
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, July 10, 2005 - 01:39 am: |
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Winfried's best guess is dead right, of course.
The latching of the shutter is not interlinked with the relase button. There is a "wind-lock" of course but that is not the essence of the enquiry here.
There is a small bias spring ( a wire loop spring) on one of the shutter activator-ring pins. It's only a very light bias and its purpose is to prevent the shutter blades opening during the cocking stroke. My best guess is that such little spring is dislodged. This would account for the shutter opening during the film advance lever-wind stroke (when there is a film in the camera). My qualification about the need for a film in place is because it is the rotation of the film sprockets which actually cock the shutter. But I digress.
Paul - Access to the shutter mechanism is through the front end - but Vito B's came in many incarnations and just about every one of them differed in construction to the extent that there is no universal stripdown procedure to get into the actual shutter mechanism.
The commonalities are that the iris is to the front of the shutter and the actual shutter blades are the rearmost components as can be seen through the film-plane. You might fall into the common trap of stripping apart the immediate front end including the iris mechnism whereas in fact the iris components and front element group come off as a complete module.
The Prontor SVS model also requires a custom-made tool to release the brass ring in front of the shutter cam-plate.
You could proceed on a "suck it and see" basis - but some of the Vito B models are easily wrecked. You might want instead to entrust the camera to someone who is familiar and experienced with whatever your particular model.
Hope this helps . a bit.
Stuart Willis |
paul
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, July 11, 2005 - 12:42 pm: |
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thank you both for your advice. since you mentioned the wind lock stuart, is it possible that the wind lock is not engaging and this is causing the shutter to be released at the end of the winding cycle? (the shutter doesn´t open till the end of the wind - theoretically one could still photograph with it).
otherwise i´ll take a look at the shutter mechanism.
paul |
Stuart Willis
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, July 12, 2005 - 07:13 am: |
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In answer to your question, Paul "No" I don't think so. The wind-lock on the Vito B comprises a latch on the main film transport plate as spanning the top of the camera beneath the top-plate. It is true that the latch is close to the shutter-release but even if the latch were not catching, it would not cause the shutter-release plunger to descend and trigger the shutter.
You do not say that you are observing the shutter-release plunger descending at the end of the cocking-stroke. I feel sure you would have said so, if this were the case. Regardless - I cannot imagine how such could occur.
If the shutter is opening (blades opening and closing quite slowly) on the film advance/cocking stroke - then the activator ring ring reverse-bias spring is not doing its job.
If however the shutter is actually firing at the end of the cocking stroke and the blade speed seems to be consistent with whatever shutter speed you have set - then the main shutter cocking cam is letting go at the point where it should latch.
In either case however - the fix is to be found by exposing the shutter mechanism. There is no work-around, unfortunately.
Best
Stuart |
