Problems mounting lenses on a MIR.

SCOTFORTHLAD

Slow learner,but keen!
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Jan 20, 2006
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Just loaded up my Mir with film after hopefully sealing a troublesome light leak.Strangely I cannot screw either my Industar 61,or Fed collapsible,more than halfway into the mount,but a black J8,and a silver J12,are accepted without any problem at all.Another FSU quirk?
Over the years I have fitted lenses to 7 screw mount FSU cameras,and this is the first instance of this happening.

Brian.
 
Brian,

looks like that camera is a right pain for you!

I can't offer any help, but good luck!!
 
Hallo Brian,

The trick is to set the lens to minimum focussing distance first - then it goes on fine.

I had the same problems with that same camera, but I;ve mounted a VC 21/4, J-9, 3 J-8s, I-22, I-50 (coll) err.. ooo and the I-61 that came with the camera.

I had some problems mounting a J-8 on my iiia before Christmas, it seemed to get tight about halfway on - I stupidly decided to force it and it fitted fine and all has been good since.
 
I've tried to mount a collapsible FED on both my FED-2 and Zorki 4 camera, but it won't fit. The mounting ring is thicker and will prevent the lens from locking to infinity. It only fits my Fed1 and Zorki1 cameras. The industar 61 shouldn't cause any problems.
 
Try giving the threads on the lens and the mount a good clean Brian , An accumulation of fine dust and grit plays havoc with fine pitch threads .

Failing that , put the MIR in a cupboard and wait for the Kiev to arrive , end of problem :D ;) :p




Paul
 
...maybe unload the film, open the shutter on B and when mounting the lens look through the film gate what's wrong...
 
Thanks guys!Not a real problem as I have two perfectly functioning lenses,but--

I'll experiment a bit more.I've been loath to force too much--but after all this is all solid stuff from you know where!:)

Brian.
 
Screw the lens in as far as it will go plus a quarter of a turn then unscrew half a turn , repeat until the lens is fully screwed in just resist the urge to force it in . It could be that at some time in the cameras past life a lens has been screwed in along with some dirt or grit , Given enough force this will stretch the thread thereby altering it's pitch , especially with a fine pitch thread , the above method should help to equalize the discrepancy .



Paul
 
Hi Brian,
Check the vertical position of the focus cam preferably with the back off. It could be that it is displaced and causing the lens to jam. I have had this on a couple of FSU cameras and it only seems to affect some lenses.;)

BTW where was the light leak from. I must get round to sorting mine out.

Kim
 
Loosen the screws on the lens mount then go back and tighten them evenly alternating sides and tightening a little at a time. If one side is too tight ,it warps the mount causing the problem you describe. That will probably fix the problem.
 
Screwy said:
Screw the lens in as far as it will go plus a quarter of a turn then unscrew half a turn , repeat until the lens is fully screwed in just resist the urge to force it in . It could be that at some time in the cameras past life a lens has been screwed in along with some dirt or grit , Given enough force this will stretch the thread thereby altering it's pitch , especially with a fine pitch thread , the above method should help to equalize the discrepancy .



Paul

Thanks Paul,
(Reminds me of a tip that my late father-in-law gave me when I was wet behind the ears,,and couldn't release a nut on some plumbing.He would give the nut a quick tighten up,and the turn the opposite way,and they would always loosen.)

Brian.
 
Kim Coxon said:
Hi Brian,
Check the vertical position of the focus cam preferably with the back off. It could be that it is displaced and causing the lens to jam. I have had this on a couple of FSU cameras and it only seems to affect some lenses.;)

BTW where was the light leak from. I must get round to sorting mine out.

Kim

Thanks Kim,
I'll check that out.

Kully has done most of the work on the light leak,checking screw holes etc,and applying some felt inside the bottom of the case and shutter housing.I've replaced the light sealing gasket under the lens mount.Hopefully this will all have done the trick.Fingers crossed!!

Brian.
 
DaveP said:
Loosen the screws on the lens mount then go back and tighten them evenly alternating sides and tightening a little at a time. If one side is too tight ,it warps the mount causing the problem you describe. That will probably fix the problem.

Thanks Dave,
Coincidentally I recently removed and then refitted the lens mount to replace a light seal,so you may have hit the nail on the head.

Brian.
 
Yes, I had to do the cleaning of the threads to install a Jupiter.12 at one time. I couldn't see a trace of anything, but I cleaned, cleaned, cleaned... both lens threads and camera threads. I used a soft toothbrush so I could get down in the grooves. Each time I would clean, it would go on a little further, so I just kept scrubbing and trying until it finally went on. I then added just a very, very slight film of light oil with the tip of my finger. Good luck, keep workin' at it.
 
I believe thats it as I just did this myself. A couple of lenses wouldnt screw on all the way, I loosened then retightened the mount properly and then all lenses would fit . I had removed the mount to set the flange distance.
 
This camera is causing you some grief eh?

Before anything else, take the mount off again and make sure none of your new light-seal is obstructing it and preventing it seating properly. Tighten the mount screws in an "X" pattern and don't overdo them, the mounts are aluminium and easily distorted. Clean the lens and mount threads too. Good luck! I'd also echo the advice to take the back off and, with the shutter locked open, try to see if there's any interference from the rangefinder cam
 
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