Jupiter-3 aperture ring alignment

kermaier

kermaier

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I just picked up a pretty nice 1960 J-3. Annoyingly, the aperture ring doesn't line up with the index marker (wide open, the index mark falls at around f/1.8). Does anyone know if this is any easy DIY fix?
(Posting in this forum, despite absence of the principal mad scientist. 🙁 )
Thanks,
Ari
 
Basically, the aperture can be moved if you loosen the set screws. The main challenge is that to screw them back in once the ring is aligned, you'd need to tap holes. Otherwise the screws don't go in all the way and won't hold very well.

Unfortunately I can't help with how to tap the holes. Thats still on my 'learn to do on a cheap lens' list. 🙂
 
Yeah what Brian said. Although you can give it a go without tapping and see how well they hold. Just unscrew them all (three) couple of turns, re-aling and tighten.
 
I tried that once. At least in my case, the screws really stuck out enough that it was worth having dealt with professionally as I was both concerned about the screws falling out and tiredof scraping fingers on them.

Who knows, your screws may be different.

For those who have tapped holes, how do you do it? I assume the produce was something like mark the lens where the holes go, take the aperture ring off, drill holes with a hand drill or dremel?
 
I recall Brian S. having said that he used a hand drill and 000 drill bit for this sort of work. I would shy away from a dremel only because it would be very easy to go too deep, and drill completely through the lens barrel, instead of creating a dimple.
 
I would think there is a much easier option than drilling into the lensmount, also thinking that when the lens was original, no extra drilling would be needed to get things lined up.
The numbers are not corresponding with the f-stop mark, if the lens module has been out of the barrel for instance for servicing and wasn't put back adequate.
Therefore try the following: get the lens module out of the barrel. Clean the threads thoroughly, put a very little oil at the end of the thread and put back in, thereby turning the lensmodule as far as possible. Normaly this should line up the f-stops again.
 
No, as soon as you add or remove shims, the screwed in lens module will stop at a different end position and therefore the aperture ring numbers will not correspond with the f-stop mark any more.

Cheers,
Uwe
 
Uwe_Nds said:
No, as soon as you add or remove shims, the screwed in lens module will stop at a different end position and therefore the aperture ring numbers will not correspond with the f-stop mark any more.

Cheers,
Uwe
Click to expand...

the OP didn't mention that shims were added or removed. If it is a lens that is mingled with, that's indeed another question....
 
OK, I unscrewed the optics module from the focus mount, and screwed it back in tight. Lo and behold, the markings now line up! Not to mention that it seems to focus a bit more accurately now... Thanks, Ron!

And thanks to all for the info and advice. I suspect I'll one day try my hand at various forms of more invasive surgery -- but with a beater lens I won't mind killing on the table. 🙂

Ari
 
buzzardkid said:
Still love those Sonnars, and the original Zeiss design. Tough and easy as pie to assemble and service.

Happy shooting, Ari!
Click to expand...

Thanks, Johan. Having taken a quick peek inside, it does seems like a very simple physical design. I'm not sure about how tough the lens is, though -- the barrel seems to be made of very flimsy aluminum, at least compared to it's contemporaries from Nikon and Canon.
 
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