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Xwhatsit
Tinkerer
Username: Xwhatsit
Post Number: 3
Registered: 02-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, January 05, 2011 - 02:43 pm: | 
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Hello,
Was a sunny day at the beach so took my new Yashica YF. After souping the shots, noticed that 1/1000 (which I've hardly used yet) was capping rather badly.
The YF is a Nicca 5L facelift, which in turn was basically a fancy Leica-M style body with screwmount innards. As far as I am aware, it's a pretty typical Barnack shutter, with the slow speeds on the front etc.
I read about shutter capping, and after doing the CRT shutter test I decided that the 2nd curtain did have too high a tension.
Pulled off bottom cover, looks like somebody has been in there before. The YF has these interesting ratchet and pawl adjusters for shutter curtain tension. I backed some tension off (way too much, curtain wouldn't run the whole way), then tightened it up. It stopped capping, but the speeds were too slow.
So I spent an hour or so fiddling around with the second curtain's tension. Here are the weird things that are happening now:
Sometimes the shutter doesn't release properly on 1/1000; you press shutter release, first curtain is released part way (maybe the gap at 1/1000?) and the shutter won't continue. It'll usually carry on once you take your finger off the shutter release. Before I touched the 2nd curtain tension, it'd do this occasionally on 1/30 - 1s. This problem seems to be OK now with the current curtain tension I have it set to (which is slow).
When I up the curtain tension slightly (I think), 1/1000 starts capping in a different way: instead of closing the gap towards the end of the shutter cycle (classic 2nd curtain too tight, right?), the "fade" is at the beginning of the cycle instead. Doesn't happen every time.
Do these two things point to a problem with the shutter release mechanism instead of curtain tension? Or do I need to start adjusting the first curtain too?
Last thing: right now I know the second curtain tension is too low. Shutter speeds look too "wide" on the CRT screen. This has affected (I assume this is the cause) the slow speeds: 1 second sounds more like 1.5 or 1.75s. Not too worried about that yet, until I get the fast speeds right. However B does an interesting thing; unless the slow speed dial is on 1/30, when you take your finger off the shutter release, it'll run through the 1 second escapement or whatever you have it set to before closing the curtain. I can't remember if it always did this! I don't think it's right though.
I'm going to build a three-sensor shutter tester for my sound card during my lunch break today and that might give me a clearer picture (no CRTs at work either, ha). Focal plane shutters are a pain! I thought I was going to be in for a treat after fiddling with the microscopic springs and gears and levers in Compurs, but I wish I was dealing with a leaf shutter right now :P. Oh well, I suppose the frustration will pass when I understand what is going on. |
T6nn
Tinkerer
Username: T6nn
Post Number: 13
Registered: 06-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, January 08, 2011 - 01:23 pm: |
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It is been said that adjusting the curtain tension without checking the state of the lubricants first in the old shutter can only make things worse. As for that you need to disassemble the shutter anyway, the best advice I can give is to find a repair manual for your camera, or at least for a similar screw mount Leica. I have a Leica IIIf repair manual as a pdf, if you are interested. |
Xwhatsit
Tinkerer
Username: Xwhatsit
Post Number: 4
Registered: 02-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, January 08, 2011 - 05:02 pm: |
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Cheers T6nn.
I appreciate what you say. My idea was to try adjusting the curtain tension first (as it looks like somebody has been in there before), and the results at first looked like classic too-high second curtain tension. Most of the leaf shutters I have disassembled haven't had any problem with lube, even the 1930s Compur on my Rolleicord. So I was hoping I could get away with an adjustment.
It looks like a classic Barnack shutter, so whilst I can't see any information (not even a user manual) around for a Yashica YF, I think a IIIF manual would do rather well! I'd love to have a look at that PDF. I'll send you a PM with my email address.
Thanks,
-Tom |
T6nn
Tinkerer
Username: T6nn
Post Number: 14
Registered: 06-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, January 09, 2011 - 06:03 pm: |
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Tom, I haven't received your PM for some reason. Please send it directly to: tonu dot tonu at gmail et cetera... |
Wonloo
Tinkerer
Username: Wonloo
Post Number: 16
Registered: 07-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, January 11, 2011 - 05:17 am: |
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My two-cent experience: before making any adjustment to your shutter, make sure the readings of your testing is consistent. Ten readings out of ten tests of the same setting (position of the photo sensor, aperture and speed of the shutter) should be within 1%. Otherwise, you have either a bad tester (electronic, unlikely) or dirty shutter (mechanical, mostly likely). |
Mareklew
Tinkerer
Username: Mareklew
Post Number: 220
Registered: 03-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, January 13, 2011 - 11:28 am: |
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If:
1) barnack shutter is capping
2) somebody was there before
3) the shutter after releasing some tension is slow/stops, then for the diagnosis read 3-2-1. The shutter was slow, somebody got in and upped tension so it's capping now. Proper course of action: clean is up, lube right and suddenly it will work - provided springs were not damaged by too high a tension...
greets!
Marek |
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