HOW TO: FED & Zorki Curtain tension.

[fidget]

Hi, you have a problem which I think that i have seen on my FSU cameras several times.
I hope this helps, see thread....
http://www.rangefinderforum.com/forums/showthread.php?t=49845

 

[fidget]

Just recently I have been hit by minor GAS and have acquired a few M42 cloth shuttered SLR bodies. Zenit, Fujica ST605, ST705, Cosina CSR, CSM (there may be more on the way!)
The preliminary checks that are described at the beginning of this tutorial are relevant to these shutters as well, although the mechanics of adjustment is obviously not the same.

Performing these simple checks has shown a sticking 2nd shutter curtain on one and fairly serious fade as the curtains slow whilst travelling. Seeing these has helped to avoid the disappointment that the first test films would have brought. It is, of course, no surprise that 30-odd year old SLR bodies may need a service to rectify these points...

 

[Denis M.]

Check that the curtains work on the ”B” setting, failure of the second curtain to be released can be a problem in the selector/release mechanism or low spring tension on the second curtain. Press the shutter button as you might in normal use, both gentle, gradual presses and more enthusiastic jabs, it makes a difference to the mechanism.

If all is OK, carry on to the more detailed checks.....

Hi fidjet, I've got a problem of this sort (release mechanism). Could you read my thread "lens de-centered" and tell me what you think. Thanks, Pitxu.[/quote]


I just got a FED 2 and once in awhile the 2nd shutter curtain will release itself and start its travel at the same time as the first, producing no gap. This is most pronounced on bulb, but it will also happen occasionally at 1/25 as well. Is due to the selector/release mechanism on the second curtain ?

The camera came with a lot of debris in the rails and the shutter dragged, spraying a cleaning solution seemed to cleared the shutter from dragging, except then this popped up.

 

[fidget]

Given that it's all clean and lubed, the part of the release mechanism which traps the second curtain isn't doing its thing. This is usually because the shaft which carries the crescent shaped catch is sticking (not cleaned or lubed properly). The shaft works on a very fine spring in two dimensions so is easily upset.

This question would probably be better posted in the FSU section as a new thread. More members will chip in with help.

This has been covered recently and is in a thread with some good detail. I will try to search it out.

 

[mynameislee2]

Don't have a CRT monitor or TV, what's the alternative?

Don't have a CRT monitor or TV, what's the alternative?

Hi,

My curtains need adjusting but this technique relies on a CRT monitor or TV. I have neither, all the monitors and TV's in my house are flat screen. I'll probably venture over to my parents as they aren't quite as up to date 🙄.

Is there an alternative way of checking without a CRT?

Regards,
Lee

 

[oftheherd]

Just recently I have been hit by minor GAS and have acquired a few M42 cloth shuttered SLR bodies. Zenit, Fujica ST605, ST705, Cosina CSR, CSM (there may be more on the way!)
The preliminary checks that are described at the beginning of this tutorial are relevant to these shutters as well, although the mechanics of adjustment is obviously not the same.

Performing these simple checks has shown a sticking 2nd shutter curtain on one and fairly serious fade as the curtains slow whilst travelling. Seeing these has helped to avoid the disappointment that the first test films would have brought. It is, of course, no surprise that 30-odd year old SLR bodies may need a service to rectify these points...

Look forward to a tutorial on the Fujica SLR's (if needed). My ST 801 and 901 cameras are fine so far, but one never knows. Fujica made cameras apparently to a pretty high standard. I think they intended to break into the pro market, but didn't market well as such. By the time they decided on a bayonet mount, I don't think they had kept up with the quality control. Maybe they just moved too fast. Their AX3 seems to have held up well though.

 

[fidget]

Look forward to a tutorial on the Fujica SLR's (if needed). My ST 801 and 901 cameras are fine so far, but one never knows. Fujica made cameras apparently to a pretty high standard. I think they intended to break into the pro market, but didn't market well as such. By the time they decided on a bayonet mount, I don't think they had kept up with the quality control. Maybe they just moved too fast. Their AX3 seems to have held up well though.

Yes, I too would like to see instructions on how to service these and solve elementary problems. I just love the feel of the Fujicas. A quick reccy under the base cover really put me off having a go.
Now my 35mm gear repair efforts are going on hold for a year whilst I get some use out of the gear (MF mainly) that does work. Got to get back on track, piccies not cameras.....

 

[fidget]

Hi,

My curtains need adjusting but this technique relies on a CRT monitor or TV. I have neither, all the monitors and TV's in my house are flat screen. I'll probably venture over to my parents as they aren't quite as up to date 🙄.

Is there an alternative way of checking without a CRT?

Regards,
Lee

Hi Lee,
I guess that at one time everyone had access to a scanning screen of some description. Perhaps there are other ways of doing this. A trip to yesterworld may be in order....good luck...

 

[rxmd]

Hi Leea,

My curtains need adjusting but this technique relies on a CRT monitor or TV. I have neither, all the monitors and TV's in my house are flat screen. I'll probably venture over to my parents as they aren't quite as up to date 🙄. Is there an alternative way of checking without a CRT?

The slower speeds (1/30 to 1/125) can be adjusted using a turntable using this method, but having a turntable around is also somewhat unusual nowadays. The really slow speeds (1/30 and slower) can be tested using a digital camera that can record video as per this thread (but it's unreliable for 1/30, especially if you don't know the exact frame rate of your camera).

The main point of the TV and the turntable is to provide fast-moving objects with a clearly defined speed. As long as you have something like that at home and know the numeric values, you can improvise similar testing methods yourself, but it takes some being comfortable with numbers.

Alternatively, you might build a shutter speed tester yourself. There's a lot of articles on the Web that describe how to build one - ranging from the simple to the intermediate and the elaborate. We've also had a couple of threads here at RFF, including a fairly detailed one.

Philipp

 

[Denis M.]

Given that it's all clean and lubed, the part of the release mechanism which traps the second curtain isn't doing its thing. This is usually because the shaft which carries the crescent shaped catch is sticking (not cleaned or lubed properly). The shaft works on a very fine spring in two dimensions so is easily upset.

This question would probably be better posted in the FSU section as a new thread. More members will chip in with help.

This has been covered recently and is in a thread with some good detail. I will try to search it out.

I sprayed a cleaning solution on the bottom protruding rod and that seemed that have fixed the issue. It wasn't popping out all the way.

 

[payasam]

My FED-2's shutter is running fast, fidget, leading to under-exposure. I plan to rotate both nuts a half turn at a time. Do I rotate them clock-wise?

 

[Frontman]

The first thing you to is remove the lock screw from the nut. You have to be careful when making shutter speed adjustments, if you loosen the lock nut without using a screw driver to hold the spindle screw in place, it may turn fully out, and you'll completely lose shutter tension.

First, set the screwdriver in the spindle screw, and then turn the lock nut slightly counter-clockwise (if I remember right). Turn the spindle screw in the same direction to decrease tension, then, using the screwdriver to keep the spindle screw in place, tighten the lock nut and replace the lock screw.

You should try to adjust only the leading curtain, and just enough to bring it down to speed. If you get any capping, then reduce the tension to the following curtain as well.

 

[payasam]

Thank you, Frontman. I first turned the nuts clockwise a half turn each. That did not seem enough, so I turned them another full turn each. That seemed to be too much, so I went back a half turn each. The speeds seem better now, when seen against my monitor's screen, but I shan't know if they are right until I do tests on film.

 

[payasam]

Not good enough -- still getting underexposure. So I exposed several frames of the last roll with aperture set to meter recommendation for 1/100 sec. but with shutter at 1/50 sec. Perfect. I shall stick with this and not tinker more.

Something I do not understand. I did a series of exposures of a blank wall, starting at 1/500 and f/2 and going down to 1/50 and f/5.6. I did not get the same negative density: the fastest speeds were underexposed. This means that the speeds are not linear. Why this should happen with a shutter whose curtains should move at a constant speed, with only slit width varying, is beyond me.

 

[fidget]

I didn't notice these new posts for a few weeks!

It's sometimes seen when testing shutter performance that the gap can be irregular, having a slightly different gap over a few actuations at the same speed. I had put this down to a slightly poor setup on the release mechanism, but never really chased "why".

The actual shutter speeds are notoriously approximate, but I too would expect that their progression would be fairly linear, most certainly between two adjacent speeds.

A few on this forum have used electronic shutter testers. It would be interesting to learn how they found the speed progression.

Dave

 

[randomm]

Thank you for this precious info! I managed to tighten my Zorki 4K's second curtain, as it was really sticking with slow speeds (actually sometimes even with 1/30s which I now understand not being a slow speed).

Unfortunately I don't have a CRT monitor or TV at home so will have to check synchronisation at work later, however, I have encountered another problem: after tightening the second curtain axle by two full turns everything else seems to work fine, except now 1/30s speed occasionally acts like B ... anyone got any idea what's going on? Do I have to pull it completely apart for lubrication (not looking forward to that!)?

 

[wolves3012]

Thank you for this precious info! I managed to tighten my Zorki 4K's second curtain, as it was really sticking with slow speeds (actually sometimes even with 1/30s which I now understand not being a slow speed).

Unfortunately I don't have a CRT monitor or TV at home so will have to check synchronisation at work later, however, I have encountered another problem: after tightening the second curtain axle by two full turns everything else seems to work fine, except now 1/30s speed occasionally acts like B ... anyone got any idea what's going on? Do I have to pull it completely apart for lubrication (not looking forward to that!)?

To answer your post in two parts:
First, two turns is a lot to have to add to make the second curtain close, almost certainly it suggests a proper CLA is needed. The "fix" is likely to be temporary I'm afraid. A second common cause for some speeds hanging is the spring that tensions that catch, it can put too much pressure on. This is more common at higher speeds though.

Second, why 1/30th acts like B. The second curtain is released by a catch, the crescent-shaped arm partially around the shutter speed selector. That catch is released by one of two things, either the first curtain reaching the appropriate position or by the shutter button being released. If it fails to get released by the proper mechanism (in this case the end of the first curtain's travel) then that adds more weight to the need of a proper CLA.

If you fancy braving it yourself, I wrote a thread specifically on the Zorki 4/4k which is stickied on this sub-forum,

 

[wolves3012]

It's sometimes seen when testing shutter performance that the gap can be irregular, having a slightly different gap over a few actuations at the same speed. I had put this down to a slightly poor setup on the release mechanism, but never really chased "why".

The actual shutter speeds are notoriously approximate, but I too would expect that their progression would be fairly linear, most certainly between two adjacent speeds.

Fidget,

I can shed some light on possible explanations. First, as I'm sure you know, the curtains are not in any way linked and their speeds are not guaranteed to be the same. Second, on some models there is no positive latch for the cocking mechanism, therefore it's possible to cock it slightly short of 100% of the way, leaving a slightly variable exposure. Thirdly, on models with slow speeds I find that 1/15th is often inconsistent, this being due to how critical it is for the slow-speed mechanism to be wound to a small and *exact* extent, which the design doesn't really lend itself to. When using 1/15, I tend to set 1/8 then back off to 1/15. If re-cocking at 1/15 I'll wind it absolutely and very firmly to the stop.

 

[randomm]

To answer your post in two parts:
First, two turns is a lot to have to add to make the second curtain close, almost certainly it suggests a proper CLA is needed. The "fix" is likely to be temporary I'm afraid. A second common cause for some speeds hanging is the spring that tensions that catch, it can put too much pressure on. This is more common at higher speeds though.

Second, why 1/30th acts like B. The second curtain is released by a catch, the crescent-shaped arm partially around the shutter speed selector. That catch is released by one of two things, either the first curtain reaching the appropriate position or by the shutter button being released. If it fails to get released by the proper mechanism (in this case the end of the first curtain's travel) then that adds more weight to the need of a proper CLA.

If you fancy braving it yourself, I wrote a thread specifically on the Zorki 4/4k which is stickied on this sub-forum,

Thank you very much for the info. Looks like I'm going to have to try to find a clear slot of few hours to have a proper look inside the camera. Don't get me wrong, I love tinkering with cameras - just have a pretty demanding 6 month old boy in my hands so finding time to tinker is a challenge!

 

[davip]

Hi!

I'm looking for an answer to my Fed 5b .

I have this video:

http://www.youtube.com/watch?v=8U4doaR5JGo

What happens is that in B mode, the curtain doesn't stay.

I have tried to adjust the speed of the curtains, but doesn't work.

All other speeds i think they are working good.

Only B mode and 30 i think they are wrong.

Hope that you have an idea!

David