Jupiter-8 on Leica??

[pb908]

I have zorki4 with jupiter-8 50mm, I have run some roll test, and the result looks good. Focusing looks like have no problem, both result,viewfinder & scale on lens agree.

but when I try to couple this Jupiter to my M2 and rollei 35rf (m-mount), both M2 and 35rf viewfinder disagree with the focus scale on jupiter. M2 and 35rf don't have problem with other m39 lens+adaptor, except with this jupiter lens (well I have only 1 russian m39)

when jupiter 8 focus ring stop at infinity, the viewfinder on m2/35rf doesn't reach infinity yet. Anyne know which one is the problem? or does russian m39 not really the same spec/design mount (or movemen of focus mechanism) compare to the real leica m39 lens?

I wonder if shimming this jupiter will solve the problem, but reading of some jupiter 8 dissasembly prosess, I can't unmount the lens assembly to focus assembly. Do I need to turn the optic assy clockwise to remove it from the focus assy??

please advice, really appreciate any answer

 

[Sonnar Brian]

The FSU lenses are built to a different spec.

You can shim the lens so that the actual focus and RF of the camera all agree, but the distance scale might be off. The only way to solve the Distance Scale is to build up or polish down the RF Cam of the lens, as approprate. I've done that on two lenses.

With a J-3, you can position the entire helical in the lens mount and then shim the lens so that all three agree.

http://ziforums.com/showthread.php?t=97

 

[pb908]

Thanks for the answer, I was planning to get jupiter 12 and jupiter 9 to complement J-8 for my M2, too bad they will need some work to be use corectly.. I was happy to find cheap alternatives compare with buying real leica lens..but actually it doesn't work as easy as I thought

how about to open jupiter 8 lens assembly, do I need to put the lens mounted on zorki4 and try to turn the front metal (not the aperture) clockwise? I see a lot of picture about it, looks like the thread is left hand thread. Any idea?

 

[oscroft]

Hi pb908,

While Jupiter lenses might need adjustment in order to perform critically correctly, many people happily use them on their Leicas without any modification at all, and get good results - especially when shot stopped down a little.

I use both a J-8 and a J-12 on my Leica M bodies, and if the focus scale and RF focus disagree slightly, I just ignore it and carry on shooting - and I get good results from bargain-priced lenses.

I'd suggest going out with a few rolls of film, your J-8 and Leica, shooting stopped-down a bit, and then seeing how you like the results.

Best,

 

[Sonnar Brian]

The direction of the threads to screw/unscrew everyting is "normal" on the J-8 and other Russian lenses that I've worked on. Turn counter-clockwise to unscrew.

Only shim it if it proves to be off on the Leica. Some work quite well even wide-open. use a test target for close-up and wide-open work. Pick something so that you can judge the error, if there is one. You might get lucky.

I would suggest the Canon 85/2 as a cheap alternative to a Leica lens for your M-Mount camera.

See this thread for my J-9 work. I'm lining up another Black J-9 in LTM to transplant all the optics from the 1958 lens. Could not make it work using its original mount.

http://www.rangefinderforum.com/forums/showthread.php?t=79337

 

[pb908]

Thanks Brian, you really have lot of answer..
Let me try to open my J8 optic module, once it is opened, the rest will be (i hope) easy enough..
Can I open the focus ring first and put some oil on the optic area of optic to focus assy? Mine is very hard to open.. Grip area is just small metal area in front of aperture ring.. I hope the oil idea works..

 

[Spider67]

I also recommend the Canon 85/2 it's not as compact as the J 9 (it's longer) but it can be found for a good price

 

[Sonnar Brian]

You are best to simply grip the front of the optics module and turn. I would not put oil or solvent, it will likely get into the aperture blades. Then, you will have to remove all the glass to flood cleaned.

I've run into three J-8's that has that had the optics module cemented into the focus mount. I suspect some "lazy" repair job that used cement instead of the proper shims to set the lens. I use a ribber mouse pad for good grip. If it does not come out with that, it might be cemented in place.

 

[ethics_gradient]

Hi pb908,

While Jupiter lenses might need adjustment in order to perform critically correctly, many people happily use them on their Leicas without any modification at all, and get good results - especially when shot stopped down a little.

I use both a J-8 and a J-12 on my Leica M bodies, and if the focus scale and RF focus disagree slightly, I just ignore it and carry on shooting - and I get good results from bargain-priced lenses.

I'd suggest going out with a few rolls of film, your J-8 and Leica, shooting stopped-down a bit, and then seeing how you like the results.

Best,

Yeah, I've had no problems with the J-8 on my R3a.

 

[payasam]

I've used a J-12, as it came to me, on an M2. My J-3, though, had to be fixed -- and Kim Coxon did that with perfect results.