Kiev 2a/Jupiter-12. A Chinese puzzle!

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Grytpype

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I have acquired a very ugly Kiev 2a with a well-used black-bodied Jupiter-12 attached, and when I say "attached" I mean it is firmly jammed on the camera! Someone has obviously had a try at removing it. Several screws, including those on the mount collar are missing, and sadly they have also tried to lever it off with a screwdriver against the front-plate.

The lens is correctly positioned on the camera, the focus is set at .9 metres and the rangefinder agrees with this. There is some very slight movement between the lens mount collar and the bayonet on the camera so this is not seized. I can't see any obvious mechanical derangement and the focus ring is absolutely solid at .9 metres, with no movement at all. If am looking at the thing correctly, I think this would stop the lens turning, because the lens helical is at its end stop one way, and the camera helical is at its end stop the other. Am I right?

Hoping to be able to get some WD-40 to the helical I tried to remove the diaphragm barrel from the front, but I don't think I can do this without getting to the back of the lens, and I can't get the focus ring off without removing the barrel first. Can anyone suggest where I could introduce WD-40, where it would get to the helical but not all over the optics? From pictures on the Kiev Survival Site it looks to me as though it would have to be between the focus ring and the mount, but it looks a bit doubtful that it would get to where it is needed.

Steve.

P.S. I've never known a helical to be as totally solid as this due to dried grease. Any ideas of other possible reasons for the problem, in the lens or the camera?
 
Agreed! I thought better of that idea and was contemplating 3 in 1.

The more I think about it though, the less convinced I am that the lens helical could be seized with dry grease - it's just too solid. Is there anything mechanical that could jam it? If it was the inner helical on the camera that was locked, and jamming the RF coupling, I'd have thought there would at least be a little backlash.

My thinking about the reason the lens cannot turm on the mount to remove it is that with the lens helical seized at closest focus, the inner helical on the camera would have to turn clockwise with the lens, which it cannot do because the stop lever is already at the close focus end of its slot. Hope that makes sense.

The only practical plan I have at present is to completely destroy the front-plate! I could then remove the lens complete with the camera helical (assuming the outer bayonet mount does not mask any of the screws), detach the stop lever, and the lens should come off.

Any better ideas?

qh2j.jpg

​
 
I thought as much! I think it's possible to remove the shutter assembly, which would give you access to the back of the lens mount. I'm wondering whether there's a screw or something else mechanically jamming the lens and the lens mount together.

I'd hate to see you destroy the front cover unnecessarily. But good luck and keep us apprised.
 
Considered removing the shutter, but I don't think it would help. The camera inner helical is completely filled by the rear element of the J-12, so there is no access to the back of the lens. The focus stop lever and its mounting screw are sandwiched between the body shell of the camera and the back plate of the camera lens mount, so there is no way of removing it without removing the mount.

Since there is not a trace of movement or clearance when I try to turn the lens focus, I feel sure that the inner and outer lens helicals must be seized together, for whatever reason. I'm going to try some oil, and not worry too much where it goes. If that fails I've though of a possible last-resort way that I might be able to release the focus stop lever, which would involve bending some things, but maybe not destroying anything!
 
I really wouldn't try oil. I suggest a few drops of lighter fluid if it is indeed a case of rock hard grease.

Lenses can feel rock solid.

The game is to try and soften and dilute the old grease without getting the stuff into the optics or iris.

If you do get it moving the effects of lighter fluid are not permanent, ie it is likely that the grease will harden again in time. But by then you will know what you are up against!

I am quite sure there are some 'technicians' out there who consider a few squirts of lighter fluid to be a full CLA.

Surprisingly they still sell lighter fluid in Tesco at the cigarette counter...but you may need evidence of your age...
 
Got there!

The lens had had a bash. When I put a ruler across the front, it was visibly out of line.

I had previously tried unscrewing the diaphragm barrel from the front, but I stopped when it stiffened up. This time I kept going until, with the screws in the focus ring slackened, I could move the focus ring far enough forward to remove the three screws in the mount (one arrowed below). This enabled the lens mount collar to turn on the barrel and release the bayonet.

0ub3.jpg

​

I've checked the camera lens register, and though it is a bit out (about .002" high), it doesn't seem to be distorted, so the damage is only to the lens.

I'll strip the lens down, but I guess it is a write off mechanically. The glass is quite good though, so I'll keep my eyes open for a lens on eBay with a trashed rear element, of which I am sure there must be thousands!

Steve.
 
I have the lens apart. When I got down to the helical the inner was visibly tilted with respect to the outer. I levered the low point upward and it jumped a helical thread and straightened up, and would then unscrew!

I will clean, grease, and re-assemble, and with a bit of luck it might make a usable lens. It must be significant that the damage occurred with the lens at close-focus. Nearer infinity there would have been more threads of the helical engaged, and less chance of it being able to jump a thread.

Thanks to everyone who offered advice.
 
Although it may be fun, you maybe shouldn't put a lot of work into fixing the lens. Kiev mount J12's are practically given away on ebay.

Cheers,
Dez
 
I'm so old I remember when people fixed things and would not give a single thought to buying something new. I applaud your guts in taking on this challenge. I, too, feel it's not the lubricant that is your problem. Good luck!
 
Thanks for the comments. Getting the lens off the camera is one of those jobs where you kick yourself afterwards for not figuring it out sooner! I had the lens stripped and cleaned on Saturday. I'm away from home at the moment, but may put it back together tomorrow. It's quite an easy lens to deal with.

There is actually rather a lot of wear in the helical (possibly the main reason it was able to jump a thread), so it probably won't be a great lens, but I will try it and see. I can always go back to Plan A and look for a cheap lens with a damaged rear element.

The camera will take its place in a long queue of other projects. I may get around to it one day.

Steve.
 
Neat story. Looking forward to seeing photos you take with the lens. And I agree, even with my small abilities, it is fun to work on something and bring it back to life.
 
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