jupiter-3 + LTM adapter: total failure

[Teus]

I've bought a jupiter-3 from 1962 in fairly good condition and tried it on my M2 with a noname LTM 50-75mm adapter. Through the weekend I photographed extensively with it. I know the QC on the lens isn't that great, and focus can be off a few centimters, but my photos were out of focus by +20centimeter. also, the 50mm framelines on my M2 did not get activated.

I'll take some photos with a summicron & industar m39 at infinity/close distance to compare & doublecheck results. in this directory you can find a few samples. does anybody know what's going wrong?

 

[Spyderman]

Basically
a) soviet lenses were built to slightly different standard which can lead to focussing errors close up (read through older posts in the FSU RF section)
b) the adapter you are using can be of incorrect thickness and doesn't couple correctly to the rangefinder.

It has nothing to do with QC of Soviet lenses.

Also read this: http://www.dantestella.com/technical/compat.html

 

[Teus]

a) soviet lenses were built to slightly different standard which can lead to focussing errors close up (read through older posts in the FSU RF section)
b) the adapter you are using can be of incorrect thickness and doesn't couple correctly to the rangefinder.

Also read this: http://www.dantestella.com/technical/compat.html

I gave that page a read earlier today, it describes a focus offset of a few centimeters. as I said, I can live with that, but if you check my photos you will see the offset is way greater.

maybe the adapter is bad, I've seen photos taken with this lens on an M3 that were well-focused.

 

[Didier]

I also had a Jupiter 3 like this. The focus was TOTALLY offset. The russian seller replaced it with another sample which is "only" 5 cm off at close up, or, after adding a thin shim inside, is correct at close up but then off at infinity. Could try to adjust the collimation but I'm getting tired of that. Wanna shoot, not test and tinker.
Didier

Edit: Here's the link to a Jupiter-3 service manual from RFF member Brian Sweeney

 

[Sonnar Brian]

I can't answer about the adapter. Unless it is not of uniform thickness, it should at least let you focus the lens. If the lens is held in at a slight angle, all bets are off.

I've had several J-3's that required some big changes in the shim. My first required a 3mm shim to be added. That is a massive change. I had one with a misaligned helical that was off by 12ft for a 15ft target. You never know where that 46 year old lens has been, or who has mucked with it.

Double check the adapter with known good lenses. Then post some sample shots with a target at a set distance. I routinely use my J-3 and J-8 with a LTM to M adapter with good results. After the lens has been adjusted for the Leica.

Lots of lenses on a Leitz adapter, including a shimmed J-8, in this thread:

http://www.rangefinderforum.com/forums/showthread.php?t=53811

J-3 on a Leitz LTM adapter, on the Bessa R2, Here:

http://flickr.com/photos/oldcamerapictures/sets/72157602481458663/

I replaced the front element of the 1959 J-3 with one made in 1986, then shimmed it for the Leica. The original front element was very scratched up.

 

[Teus]

I also had a Jupiter 3 like this. The focus was TOTALLY offset. The russian seller replaced it with another sample which is "only" 5 cm off at close up, or, after adding a thin shim inside, is correct at close up but then off at infinity.

ah, looks like its not that uncommon. I'll contact the seller and see if he can replace it. the screws and rings on the J-3 have some wear, so it's possibly somebody disassembled it and failed to re-assemble properly

I've had several J-3's that required some big changes in the shim. My first required a 3mm shim to be added. That is a massive change. I had one with a misaligned helical that was off by 12ft for a 15ft target. You never know where that 46 year old lens has been, or who has mucked with it.

well, I've got a crappy and loose Industar lens, but it's been verified to work on M-mount by its seller.

please explain me a bit how the focus/shim system works. I can see the focus cam moves forward when you focus more closely. m39 is supposed to focus well at infinity, but focus gets off when you focus more closely. If shimming is the only solution for close focusing accuracy, how does it affect infinity focus?

 

[Teus]

I'm checking your disassembly PDF. the shim ring is about 1,5-2mm thick.

 

[Teus]

focusing at infinity is totally blurry, there's something terribly wrong with the J-3 alright. let's see if the russian ebayer refunds my shipping costs if I need to send the J-3 back, he really shouldn't sell untested equipment.

 

[Didier]

...let's see if the russian ebayer refunds my shipping costs if I need to send the J-3 back....

Mine ("moscowphoto") didn't refund my shipping costs.

Usually they look at the glass, turn the barrels a few times forth and back and then describe it as "well working" or "excellent". If they would make some more serious and labourous tests, they'll certainly state it. One that really checks, and, if needed, CLA's his items, is seller "cupog" from Slovakia.

But even with a well reputetd seller you may catch a lemon. There are so many...

Didier

 

[Sonnar Brian]

Sorry- changed my Email and could not log into RFF for a while.

If the lens is front-focussing, ie in front of what the RF indicates, the shim needs to be reduced. The optics need to be closer to the film.

If it is focussing behind the what the RF indicates, the shim needs to be thicker to move it away from the film.

The amount that the shim needs to changed can be judged by looking at the image at the film gate with a loupe; focus the camera on an object using the RF (I use a lamp for the target); and then focus using actual image at the film gate. Note how much you had to move the lens in or out to judge the change in the shim.

I have seen some lenses where the elements not being aligned correctly were the problem. I just fixed a Sonnar lens with an element in backwards. The lens actually produced an image that was center-sharp, but the edges were way off. Reversed the elements, shimmed it, works great. You lens could have an internal element out of place to produce big errors in focus.

 

[Kim Coxon]

Another thought. You need to make sure the focus assembly is correctly assembeled before thinking about shimming the lens. I had another member's J3 recently and having redone the focus unit correctly, most of the problem was solved.

Kim

 

[Teus]

If the lens is front-focussing, ie in front of what the RF indicates, the shim needs to be reduced. The optics need to be closer to the film.

I have seen some lenses where the elements not being aligned correctly were the problem. I just fixed a Sonnar lens with an element in backwards. The lens actually produced an image that was center-sharp, but the edges were way off. Reversed the elements, shimmed it, works great. You lens could have an internal element out of place to produce big errors in focus.

thanks Brian, I'll send the J-3 back and ask for a pre-1965 replacement in good condition. There's something wrong in the assembly alright, but now I wouldn't know how to track down the problem

I'll CLA a crummy Industar I have here, and work on the J3 once I know how they work exactly.