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Thol
Tinkerer
Username: Thol
Post Number: 12
Registered: 08-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, March 23, 2012 - 10:32 am: | 
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Over the years people have given me the odd camera free. Today I was delighted a Nikon F Photomic. The lenses is full of fungus, so before leaping about trying to find another Nikkor -H 1:2 lens, I thought I would check out the shutter.
All works well from B-250. 1/500 should be OK. But at 1/1000 I see no light through the shutter at all. I pulled out a few of my others including a Praktica, K-1000, and a Mamiya 1000 DTL. I can see light from the backs of the shutters on all three at 1/1000.
Are the latter three just fudging? that is to say ... are they slow? Are we supposed to see any light at 1/1000?
If the Nikon's shutter is not working at 1000, what are my chances of it being timed right (more or less) from 500 down. I'd be happy to accept 500 as top speed. The low speeds seem right on no hesitation and you can hear the proportional time differences from one second to 1/125 quite easily.
What stops a shutter from functioning properly at just one speed>
Another question what can I expect to pay for a decent piece of new glass?
Any comment welcome cheers ... Thol |
M_currie
Tinkerer
Username: M_currie
Post Number: 288
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, March 23, 2012 - 06:47 pm: |
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You should see a slit of light through the shutter at 1/1000 if you hold the camera up to the light with lens and back off.
It's not that unusual for one speed to be off and the others all right, or at least functional. It probably needs cleaning and lubing. There are also some delicate curtain tension adjustments for the high speeds.
I had an F that got wet inside, which had the same problem. I was able to get all the speeds working, and even seeming to be about right, but 1000 never came back.
I'd give it a try with some cheap print film. Find a level of light that can use a range of shutter speeds up through 500, and try it. See how the exposures vary. F's were pretty notorious for not getting up to the full 1000 anyway.
Check KEH.com for glass and you'll get a pretty good idea of normal prices. There are a lot of lenses that will fit, at a huge range of prices. |
Thol
Tinkerer
Username: Thol
Post Number: 13
Registered: 08-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, March 23, 2012 - 09:13 pm: |
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Thanks Mr Currie. This was a huge help. From what you wrote, 1000 is right off the line. But the other speeds as I said above seem OK by ear and light with the lens off.
I have always admired the way the shutters trip in early 'F''s, and the Zeiss type back is a real plus for ensuring a light seal. So I should find some new glass. So... when you say lots of lenses will fit, I am assuming only Nikkor lenses ... am I right? Or are their bayonet F-mounts? made by other companies that will fit. I've been searching for info on the net, but maybe I've just been on the wrong track.
Thanks again. |
Nick_merritt
Tinkerer
Username: Nick_merritt
Post Number: 29
Registered: 06-2008
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, March 24, 2012 - 05:46 pm: |
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I got a very well used F about a year ago, and 1/1000 didn't work -- or rather, it was tapering big time: only a small slit seemed to get exposed. It probably had been sitting for quite a while. But as the weather warmed up, and as I exercised the shutter, 1/1000 seemed to come back. Again this winter, when I took the camera out of the closet, the same thing happened. Since it's basically fully functioning except for one speed, and even that is a problem only a part of the time, I can live with that. But I'm sure a CLA would take care of the problem. |
Thol
Tinkerer
Username: Thol
Post Number: 14
Registered: 08-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, March 24, 2012 - 08:26 pm: |
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> But I'm sure a CLA would take care of the problem.
Thanks for comment Nick. I think I'll be looking for glass before CLA. Yesterday I tried to get some fungus off the prism. I took the viewer module down to where the electric connections were and stopped. I could see that a whole lot of stuff had to come apart, and I have no manual. I can live with some fungus on the prism, but the lens is ruined. I can live with 1/1000 as well. |
Thepurush
Tinkerer
Username: Thepurush
Post Number: 28
Registered: 01-2012
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, March 25, 2012 - 01:16 am: |
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I know only way to check 1/1000 without using ne other apparatus is this.
Mount a flash and open the back cover. Fire shutter looking at the shutter while camera is facing a white wall. You shd be able to see just a flash coming thru a small slit.
If you find the slit you may presume it is ok.
Remember any adjustment of shutter curtain tension affect all speeds above synchro speed (1 125? 1/60?) in cluding 1/1000. Avoid adjusting if synchro speed and 1/1000 is ok. |
M_currie
Tinkerer
Username: M_currie
Post Number: 289
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, March 26, 2012 - 07:09 am: |
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A note on the prism. It's probably not fungus, but deterioration of the coating where the prism is clamped down. There's really nothing you can do with this, since the coating itself has corroded, and there's no access to the underside of a mirror coating anyway. It's a common problem with F's, and all four of mine have this to some degree. It doesn't affect metering. |
M_currie
Tinkerer
Username: M_currie
Post Number: 290
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, March 26, 2012 - 07:16 am: |
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It's pretty easy to check a shutter for capping or dragging, etc. Take the lens off, and open or remove the back, and hold the camera somewhere near arm's length, aiming it toward a window or other bright light. When you operate the shutter, you'll see the whole frame lit evenly, if the shutter is working correctly, even in high speeds, owing to the persistence of vision. If it's not working right, you'll usually see only a portion of the frame.
I just tried this with an old F, and it works that way even at 1/1000.
You can also check flash sync operation this way, since if sync is off you won't see the whole frame, if anything at all, when the flash fires. |
Old_school
Tinkerer
Username: Old_school
Post Number: 143
Registered: 04-2011
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, April 04, 2012 - 11:14 pm: |
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T: You can also use an old style TV screen to check shutter speeds with the scan lines off the screen. Also a Florescent lamp an be used for a quick check, but this takes a little practice & good eye. |
