Kiev-4 Jupiter-12 incompatibility??

[Joao]

Hello
I need help. I have a Kiev-4a (1980) and a Kiev-4 (1964); both came with Jupiter-8 lenses that are interchangeable, both fit both cameras, as expected.
I recently bought a nice Jupiter-12 : the lens fits and focus very well in the Kiev-4a, but when I adapt in on the Kiev-4, the red dot stays at 1 o’clock position, I am unable to turn it more anticlockwise (to the 12 o’clock position, where it should be) - and the focusing scale is obviously wrong. Photos here
http://public.fotki.com/BlueWind/kiev-4-and-jupiter-12/
Am I missing something or doing something wrong??
Thanks in advance
Joao

 

[pinafore2]

same problem

same problem

I had the same problem with a Jupiter-11.

My problem was the mount on the lens that would not fit to the camera, because the "Claws" on the lens, i mean the parts of the mount that i supposed to slide behind similar "Claws" on the camera, was too thick. This meant that when turning the lens it kind of got stuck in friction.

I dismounted the mount from the lens itself and carefully, using a "Dremel" sort of machine, removed a little bit of material from the backside of the "Claws" on the lens mount, until it could fit.

I know this explanation may seem a bit unclear, but if you want some more details i can try to provide.

Per

 

[Spider67]

Same here: My black J 12 from the 80's will only fit on my 4 after a bit of (sometimes forceful) fiddling. It works without any problem on my (leaky and squeaky) 4 AM.
So that would be helful to geat some fix for that otherwise I would buy a silver J 12 (but that would be awkward wouldn't it

 

[Joao]

Some progress...

Some progress...

Hello again.
I got a tip at another forum: placing the Jupiter 12 with the camera focusing scale focused at 3.3 meters allows the red dot to rotate counterclockwise to the 12 o'clock position. So far, not bad🙂 .
However, the closest focusing distance I can get now is around 1.7 meters. The lens seems to be blocked against something (frightening doubt: rear glass pushing against the curtains😱 ???)
I look forward to get some enlightening...
Joao

Edit: The lens screws in, but focusing range is very limited, depending on the initial lens mark. No contact between the glass and curtains, it stops against a horizontal metal part slightly ahead of the shutter
J

 

[uspica]

I had the same problem

I had the same problem

The real issue is a fail in the tolerances of the "threaded" part behind the inner bayonet. This brass ring has the objective of reducing the play of the lenses once in its place, so it was given a H6 tolerance. The part of the lens fitting there (in case of the Jupiter 12 the springer ring with the bayonnette fins) has a h6 tolerance.

For anyone who is not an engineer, this means that normally it will fit tight, but if for some reason the tolerances are brought to the worse extreme IT WONT FIT"

This means you either have to dremel this brass ring from inside of the camera or the one in the lens. I dismantled the camera and worked on the "female" part, because the brass ring of the lens was too thin to work with.

Don't worry about making a mess of it, you only need to remove some tenths of a milimiter.

I did it and works great now!! This lens really is worth the worry.