Jupiter optical block stuck

[japomono]

Hi,

I know this is not a real Zeiss thing, but it seems some people here could help me.

In order to adjust focusing for Jupiter lenses (3 and 8 to be precise) one has to start unscrewing the optical part of the lens. In some cases it comes easily, but for some I just do not get the thing to move. It is stuck.

Does anybody have an idea/trick to loosen the thing ? The lens is a 75 Valdai J 3.

[Brian]

An RFF member just had the same problem. I use a rubber mousepad to get a good grip. For really tough ones, use a rubber mat around the back of the lens and another rubber mat to grasp the front. Some of them require a MAJOR twist to get out. It unscrews in the normal way: counterclockwise to unscrew, clockwise to screw in.

I've run into an occasional J-8 that was glued in. It would not budge. I think JMKELLY ran into a J-3 that had the same problem.

http://www.rangefinderforum.com/forums/showthread.php?t=79329

[jmkelly]

We're talking about the LTM lenses, right? Yes I ran into very stuck optical modules on a couple of newer J-3 lenses.

Ronsonol to the rescue, but once you have soaked the whole lens in lighter fluid for a couple of days you will need to do a complete disassembly to clean all the optical surfaces, and re-lube the focus helical and aperture mechanism.

It's worth the effort - you will end up with a lens as good as any.

[japomono]

This is very kind to answer so quickly. I will give it another try with some rubber.

And yes, this is about an LTM model.

The problem is that I had actually chosen another lens (1961 ZOMZ J3) but the seller got mixed up and sent me this 1975 one. It is absolutely mint, but needs adjustement (it focuses too close and does not reach infinity). So I am torn between sending it back and adjusting it. Thus I guess I will avoid lighter fluid for this one.

[Brian]

BTW: We love J-3's here.

To adjust for the RF cam to drive the camera to Infinity:

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

I am doing this on a 1953 J-3 now. And just received another 1953 J-3 to work on for someone else.

[japomono]

So, I got the thing off, without too much damage. But it was impossible without tools.

Now I need to find some shims, because it was equiped with only one thick shim, which actually apperas to be too thick. And I don't think I can screw the ring much more in.

[Brian]

If the lens focusses IN FRONT of where the RF indicates, the shim is too thick. You can polish it down with sand paper. I use a shallow box, put the fine-grit sand-paper in it, and polish it down with circular motions. Calipers are handy for this. How far is the focus off? How many inches at how many feet?

[japomono]

Yes, there is one single shim, more than 1mm thick. So I thought about sanding it down, but I was a little afraid of ending up with non parallel faces.

As for how much it front-focuses, I shot a quick test roll and then later made some tests with a focusing screen at the film level. I was not extremely precise, but a rough estimate is that it focuses not further than about 20 feet.

Now I actualy had also ordered another optical block from leon1965jazz on ebay, and when I asked him for shims, he spontaneously suggested I send the lens to Russia and he would adjust the block on it. Since he has a good reputation and I do not have much spare time these days, this seems tempting to start with...

[Brian]

I've bought at least 10 lenses from Leon. Good way to go.

Adjusting the lenses is much easier with the trhough the lens viewer that i was lucky to find. There are several different reasons why a J-3 cannot focus to infinity: usually it is the shims, sometimes the helical needs to be repositioned in the lens mount. I just had a "disaster case" 1953 J-3 that was rebuilt incorrectly. The helical was out too far in the mount by about 5mm. I replaced the front element with one that i bought from Leon. It works now!

http://ziforums.com/album.php?albumid=148

[japomono]

So to give the end of the story: Leon did a good job and sent back the lens very quickly. I am so far very pleased with my J-3; even wide open it can be very sharp in the center. The combination with the Fed-2 is pleasent (and beautyful, which attracts often comments and questions by bystanders :).

Thanks for your help !

[Brian]

I'm glad it worked out!

If you scan some pictures, upload them to a gallery hear. 1MByte file size, 1024 resolution, should be good to show off that J-3.

[japomono]

Here is trying the embedded flickr links (click for larger view on flickr). I'll add it to my gallery also though.

Thanlks again, Brian !

<a href="http://www.flickr.com/photos/bw94/4024476850/" title="Ju-3 by BeWePa, on Flickr"><img src="http://farm3.static.flickr.com/2658/4024476850_4bb580d6a3.jpg" width="500" height="333" alt="Ju-3" /></a>

<a href="http://www.flickr.com/photos/bw94/4039926480/" title="Le bus 199 by BeWePa, on Flickr"><img src="http://farm3.static.flickr.com/2748/4039926480_b504797eda.jpg" width="500" height="333" alt="Le bus 199" /></a>

[japomono]

Some shots wide open

<a href="http://www.flickr.com/photos/bw94/4068764779/" title="memory hole by BeWePa, on Flickr"><img src="http://farm4.static.flickr.com/3488/4068764779_008b2449c0_b.jpg" width="1024" height="681" alt="memory hole" /></a>

<a href="http://www.flickr.com/photos/bw94/4117817963/" title="spleen ! by BeWePa, on Flickr"><img src="http://farm3.static.flickr.com/2517/4117817963_29df0112f4_o.jpg" width="1200" height="788" alt="spleen !" /></a>

<a href="http://www.flickr.com/photos/bw94/4161664624/" title="Götzendämmerung by BeWePa, on Flickr"><img src="http://farm5.static.flickr.com/4037/4161664624_f92d8f61c2_b.jpg" width="1024" height="654" alt="Götzendämmerung" /></a>

<a href="http://www.flickr.com/photos/bw94/4075929443/" title="Toussaint by BeWePa, on Flickr"><img src="http://farm3.static.flickr.com/2534/4075929443_bda6671de9_b.jpg" width="1024" height="672" alt="Toussaint" /></a>

[Brian]

They look good to me!

Focus looks spot-on.

[lkgroup]

Brian, I am just curious, thinking of the lenses (J-3) that you collimated for me to Leica specs, how far off would they be if used on a Fed or Zorki (FSU) Cameras?

I'm thinking wide open and close up would be the biggest problem, but how about at mid and normal lengths?

How far would you have to stop down (Assuming they focus is off on FSU cameras) to have subjects in focus.
\
My basic questions I guess is How useful is a J-3 lens collimated for Leica standards be on the FED/Zorki cameras.

Again thanks for your work.

Leo

[Brian]

I've read that it was recommended that new lenses such as a J-3 bought for an existing camera be adjusted for the individual camera. With that in mind, I do not think the Soviet cameras were all rigorously adjusted to a particular standard as were German and Japanese cameras.

A J-3 or J-8 adjusted to a Leica camera "should be" about 1" off at closest focus with a Russian camera. BUT: individual cameras vary. MY Zorki 3M will be spot on with the Leica-adjusted J-3 because I adjusted the camera.

[japomono]

Yes, the soviet cameras' rangefinders are quite easy to adjust. So if you have a Leica and a lens adjusted for Leicas, the best is certainly to adjust the RF.