How to mount Jupiter-12 on Kiev 4am

[akptc]

Hello Kiev users. I am stuck and a bit frustrated with what I think is either my ignorance of the Kiev camera operation or the usual soviet manufacturing incompetence.

- Is there a trick to mounting the J-12 35mm lens (Contax mount) on a Kiev 4am? With some effort, I finally mounted the lens but, while it rotates smoothly when un-mounted, on the Kiev it grinds to a near stop at about 1.5m and it takes some force to twist it either way.

I can mount and use the Helios 103 and a Nikkor 135mm on the same Kiev, no problem. Is it likely that the lens mount on the J-12 is no good or is this particular lens typically hard to mount on a Kiev?

Would appreciate your advice,

 

[Chaser]

You may try setting the focus wheel to the infinity lock setting and then the lens to infinity...then mount...you may need to press the infinity lock button to clear the metal bit by the release button on the j12. Hope that helps.

 

[akptc]

Chaser, thanks, that's exactly what I did, the darn thing is still tough to move. I've seen the name "Oleg" mentioned around here, wonder if he does Kievs?

 

[physiognomy]

Hey Andy,

Seems to be a common problem, although you are unlucky because some (including me) seem to have no problems once the lens is actually mounted correctly... There are some really informative threads here on RFF with links to sites like Matt Denton's with pictorial descriptions on how to mount the J-12... Just search 'mounting Jupiter 12/J-12'.

Here is one thread that might be some help...

Cheers!

Peter

 

[akptc]

Peter, thanks! I found this piece of advice, found on the thread you linked, to work best for me: "To properly mount a J12, or J9, or J11, the lens should be set to infinity and the camera focusing mount should be turned so that the infinity mark is adjacent to the red dot on the body. This gets the lens and body bayonets nicely aligned, and a simple 1/4 turn counterclockwise brings the lens infinity mark, (and red dot) to top center and the lens latch pops into it's slot holding things together". (by Paul Connet).

Now the J12 mounts pretty well on one of my two Kievs, i.e. the lens now can be focused w/out straining my muscles 🙂, while much more force is required on the other Kiev (but still better than when I started). By listening to the lens rotate in each body, I am pretty sure I might still need to resort to some filing. Of course, that is tantamount to brain surgery with a plow, in my hands... Looks like a perfect project for when I retire 🙂

Thanks again for the help, I was desperate, now I just wonder why I keep falling for that soviet crap (sorry, couldn’t help it, it’s in my Polish blood 🙂.

Cheers,

 

[Xmas]

The lens and camera rangefinder coupling mechanisms may not be coaxial and may bind as they rotate.

There is a fix in post on this forum 14-12-2004, by Laika.


'Jupiter 12 - DIY relube (long w/images)'

See the last descriptive post.

It is easy remembering this hot linking it seems MI.

Noel

 

[akptc]

Noel, thanks for the pointer, that's an encouraging article. There is a similar one on the Kiev Survival Site. Both suggest getting a couple of special tools.

 

[physiognomy]

Hey Andy,

Glad I could be of help... I remember the frustration I first had when trying to mount my J-12... Now it is second nature.

Sorry your lens may need a little work. I braved opening the front of my Elmar 9cm the other night & think I increased my gray hairs two-fold (I now have a total of 4 🙂 )...

Cheers!

Peter

 

[Xmas]

Akptc

To align the coaxial sections you may only need a small screw driver, it may only need a few operations not the full CLA.

To strip the lens you can make do with:-

- a set of small screwdrivers
- a small pair of needle nose pliers and
- a file.

One files the needle nose pliers until the ends just fit into the lens rings.

The J12 may need a larger set of pliers to bridge the rear mount if you want to strip it completely.

You need to take extreme care if the lens rings are tight...

If you have several bodies it may be difficult to get a lens to fit each, but good J12 are reasonably cheap...

Noel

 

[Xmas]

P.S.

Andy

The J12 does seem to be a problem, they may not have been toleranced, but the adjustement seems easy.

There may also be some spread in Contax mounts, as I have problems with both a '36 Contax II and a '48 Kiev and the same J12. I need a guinea pig to tell me how easy it is to fix.

Noel

 

[Hamster]

Aside from making sure both lens and body is at infinity, I would also suggest when doing the final twisting action when mounting the lens, put your finger on the thumbwheel to prevent the inner lens mount from spinning, that will ensure the inner bayonet are engaged correctly.

 

[akptc]

Well, having read and re-read 2-3 illustrated articles on how to disassemble the J-12 I must say I am *not* up to it, just plain chicken, what can I say. I've messed up enough devices to last me a while 🙂

How about this: a free Helios 103 (either a new one or a used one, both very nice) to whoever volunteers to make my J12 fit / move like butter on one of my Kievs? I pay for shipping, of course (well, it got to be in the US). I can also throw in a few neck straps, etc., to sweeten the deal...

 

[Hamster]

Hey akptc,

Have you read this post by Xmas, perhaps you can do it yourself without disassembly:

http://www.rangefinderforum.com/forums/showthread.php?t=23191

 

[akptc]

Hi Hamster, thanks for the tip. The focusing ring on this J12 turns like butter when unmounted, it's only when mounted on one of the 2 Kievs that it becomes hard to turn at certain points. I am 90% certain it has to do with the bronze "wedges" on the mounting portion of the lens, these will have to be filed off a bit.

 

[Hamster]

Andy,

The inner barrel with the three tabs that engages the inner body mount is spring loaded, perhaps you can check if the movement of this this inner barrel is smooth, if it doesn't slide out fully or there is mechanical impedence, then one possibility for binding is it is not sliding out to engage the inner mount correctly.

If you suspect your issue is related to the tabs not being the correct dimensions, check the following correspond to your lens.

I just did a quick check using a pair of calipers on a J-12 that mounts correctly, see if your J-12 have similar measurements.

With lens set at infinity, with rear element facing you and infinity being 12 o'clock position:

The extreme left edges of the largest tab is slighty left of 12 o'clock position. edge to edge measurement using calipers: 20.9 mm

First small tab, with left (lower)edge at just before 6 o'clock position, edge to edge = 9.2mm

Second small tab, lower edge just above 9 o'clock position, 9.2mm

Hope this helps.

 

[arothaus]

Hello,

I once had problems with a J-12. The point was, that the coupling of the metering system was stiff. Usually the coupling of the lens is pressed with a spring into the inner coupling of the metering system of the camera. But often there is old grease around, so the spring mechanism can't work correct.

You won't have to unmount the complete lens to fix this problem. I recommend the "kiev survival site" for further reference.

Regards,
Andreas

 

[Xmas]

Andy

I apologise I did not mean to worry you.

The fix for the non coaxial lens and camera rangefinder problem is (or may be) simpler than you may think. I paraphrase from memory of earlier post on rebuild & relube, referenced earlier....

- undo the screws on chrome faschia embellisher of the lens mount, remove embellisher, do this over a 10x8" tray or similar screw catcher
- loosen off the revealed screws a little
- mount the lens and rotate the focus mount on lens until the lens behaves properly
- tighten screws a little in situ if possible
- remove lens
- tighten screws (recall they are little toy screws not 4x4 wheel nuts) properly
- try lens again, if not nice retry process, from 1st step

Please note you are a nice ginuea pig... as I don't believe it can be as easy as advertised earlier but it may not be as complex as you think. Note if the lens should shift later it should be easy to fix and I normally use a dab of nail varnish stolen from Mum or other gurl for critical but concealed screws, instead of torquing them tight.

If you dont want to try this then I will try on my lens for you, I don't have a digital camera or a scanner so I will not be able to post any photo help. Even a cheap digital camera is more expensive than another J12, oops more GAS justification.

Noel

 

[akptc]

Hi Noel, thanks for the note. No worries, I put the J12 aside for the moment and let the Kiev wear the 135mm Nikkor (mounts like butter 🙂).

 

[Xmas]

Andy

I tried fixing my own J12.

It was difficult, and also easy.

Procedure

a) Undo three screws from chrome facia - cover - to lens mount ring, remove facia. This exposes the mount which is held to lens body by three grub screws. The three holes seem to jave been drilled with the lens mount and lens body in a jig as the grub screws seat accuractely into recesses in the lens body, i.e. a Morse drill with a depth control has been run through the mount into the lens body in situ, and then the a bottom tap run in, so that the grub screws seat accurately into the lens body but also just clear the facia ring.

b) The next step is the problem, remove the grub screws with the lens mounted on the camera and operate the focus action to see if it will slacken off. The problem is the grubs are tight in the lens mount holes and may not go back at all easily. And although they are 'big grubs' it is easy to shear off their heads if they are tightened without the support of the threaded holes.

Any way after a great deal of struggling my J12 now is ok on both the problem Kiev and Contax, one still has a slight tight spot at 6 foot which I can ignore as I never use a 35mm at 6 foot, but I dont know exactly how I did it, apart from writing off a grub screw. The tight body was the one I did the registration on!

I'm not recommend you tried this unless you are confident in your patience...

Noel

P.S if you are stuck at stage b) a swiss file in the mount holes might help to provide more clearance in rotation (to avoid uppsetting the lens registration). The alternate of attacking the focusing coupling with a file may be easier if you can detect where the high spots are, because the interference is clearly very small.

 

[Xmas]

Andy

Gremlins - the holes to open out are the holes in the lens body rather than the holes in the mount, otherwise the grubs will strip when tightened, sorry.

Noel