Ju-3 (LTM) focus completely offset - what to do?

[Didier]

Hi folks

This morning I have received the black LTM Jupiter-3 from ebay seller moscowphoto, which I had bought for $110.00 (serial #7703537). I know infinity or close focus can be slightly offset with old russian lenses used on newer M/LTM gear. But this lens is completely out of focus. See the pictures below. If I focus on 1m, the sharpness pane is at about 35cm. Didn't know the Ju-3 is a macro lens!...

I have to add the lens was rather poorly packaged - in a envelope, not a solid box. OK the envelope was well stuffed but not protecting enough if the package is thrown around (which usually happens in every postal facility). I can't say if the focus issue is caused because of a possible shipping incidence or if it is just another bad FSU lens sample.

In any case I'll ask the seller for replacement. But does anyone here know if/how such a lens can be adjusted? I guess the focusing tubus is just offset for a few mm's. This might be the easier route to go - because the lens looks fine otherwise, and a replacement sample might be offset, again.

Another question: there's a f22 mark, but I can stop down to f16 only - is this normal?

Thanks for any advice,
Didier


Sample pictures: shot with R-D1s, ISO 200, resized to 900x600, first with f1.5, others with f4 (but with this offset even f16 wouldn't help):

 

[Didier]

Hopefully you just need to change the shim. It looks like it is too think and the lens is focussing nearer that what you want.

Kim Coxon has posted repair instructions for some FSU lenses. My J-3 instructions are there for setting the shim on the J-3.

http://www.pentax-manuals.com/repairs.htm

Brian, thanks a lot! Kim even has a detailed service guide for the Ju-3.

Sometimes I ask myself how did we get informations before the internet era? 🙂
Thx again
Didier

 

[SteveM(PA)]

That's the same seller that sold me my nasty black J3 last November. It looked nice, but it was really messed up. He felt very bad about it, and offered a replacement, which I denied (because I had already sent the lens to Yuri. We were never able to get it to work, and Yuri ended up buying it from me I think for $60. (Payed $110 for it plus two fedka CLAs that didn't help.) I've given up on a black J3.

http://www.rangefinderforum.com/forums/showthread.php?t=31065&highlight=j3+stiff

 

[brachal]

It sounds like the aperture is also messed up. It should go all the way to f/22. I'm sure this is very frustrating. It's a shame because, IMO, a good J-3 is just about as good as they come. Good luck.

 

[xayraa33]

the black J-3 seems to be a real gamble at getting a decent one.
the quality control, if any , took a nosedive.
It makes me wonder about the great number of late J-3 lens assemblies for sale from the FSU.
Where these made so bad that it was not worth to put them in lens barrels?
even by the lax Soviet standards for consumer goods.

 

[thafred]

ha, thats the same seller my decentered J3 came from!!! It even was catched by Customs so I had to pay 20% tax and wait three weeks!! *grrrr*

I guess brian is right and the lens needs a slimmer shim! best to get yourself a ground glass and a good loupe (21mm color skopar rules) and try to nail the focus because you can see the perfect zone of focus in realtime (and don´t have to take shots and watch on the lcd)

I love my J3 and judging from the bokeh in your shots, you´ll love yours too (at least when there will be a plane of focus somewhere ;-))

 

[Didier]

Update: the supposedly too thick shim used in that lens was a 1mm shim. Had no other shims in that diametre but then tried it without shim at all. The focus was still much too close, even when a bit better than before. Did not want to tinker on and carefully rescrewed the lens together; and sent it back to the seller moscowphoto (Mikhail Lushkov) who had offered to send me another sample. Let's hope this one will be better.

 

[ZorkiKat]

the black J-3 seems to be a real gamble at getting a decent one.
the quality control, if any , took a nosedive.
It makes me wonder about the great number of late J-3 lens assemblies for sale from the FSU.
Where these made so bad that it was not worth to put them in lens barrels?
even by the lax Soviet standards for consumer goods.

Never trust an old object which still looks new! 😀 One reason why it never 'aged' is that it was probably kept after the original owner realised that it didn't work.

I would trust a J-3 whose barrel looks a bit tired- even throw in a few, minor cleaning marks- as these are proofs that the lens really got used, and therefore, worked right. Consider too, the presence wipe marks on the glass, a working lens had to be cleaned when dirt and finger prints got on it while being used. And its barrel would look a really used, from all those turns it got through the years of use.

My two J-3 are in such condition. Not cosmetically nice, but focuses on the dot. And they would even work with the Leica. Without any adjustment whatsoever.

Jay

 

[ferider]

I very much agree, Jay.

Sorry for your troubles, Didier.

Roland.

 

[40oz]

moscowphoto is the seller that sent me a fantastic silver LTM J-3 instead of the mint black one I bid on. I returned the silver J-3 (against my better judgement), and never received the black one. I did eventually get a refund, but the whole thing was a mess.

 

[Didier]

Today I received the replacement Ju-3 from seller moscowphoto (Mikhail Lushkov). This time it looks I'm a bit luckier. The sample focuses +/- correctly, ecept close up where it focuses approx. 5cm behind. I guess this is inside the tolerance of Jupiters and Epsons as well. The focus ring is bit stiff. I'll try to CLA that Jupiter myself thanks to the great tutorial of Kim Coxon.
Didier

 

[rxmd]

I think Kim's tutorial doesn't cover black Jupiter-3's as they're mechanically a bit different.

 

[Didier]

I think Kim's tutorial doesn't cover black Jupiter-3's as they're mechanically a bit different.

Will try it anyway! Thx.
D.

 

[Sonnar Brian]

I wrote the J-3 repair Tutorial that Kim hosts on his website. The Black J-3 is different only in how the rear optics module is mounted. Changing the main shim and collimating should be identical to the chrome one shown. I've made one "panda" J-3 with a 1957 focus mount with a 1984 optics module. The spec sheet that came with the Black J-3 optics states that they are 52.5mm focal length, confirming my suspician that they were built to the Contax standard. Kiev mount lenses were always in chrome, so these modules are for the 39mm thread mount version.

The tutorial is meant to be helpful to those wishing to collimate the lenses for their Leica's, or FSU camera's if need be. It is not an advertisement. Aside from those RFF members that have written to me already, I am not taking in any more lenses for "adjustment".

 

[rxmd]

The tutorial is meant to be helpful to those wishing to collimate the lenses for their Leica's, or FSU camera's if need be. It is not an advertisement.

Don't worry, I don't think anyone claimed that the tutorial was an advertisement. In fact before you posted the previous post here I wasn't even aware who the author was. 😉

Aside from those RFF members that have written to me already, I am not taking in any more lenses for "adjustment".

That's certainly a pity. Any particular reason or just the general lack of time and feeling of elapsing lifespan that we all share? 😉

Philipp

 

[Jocko]

That's certainly a pity. Any particular reason?

Philipp

Indeed it is, because Brian is one of the most knowledgable and genuinely helpful members this forum has ever had.

But then, "against stupidity the very gods themselves contend in vain".

Ian

 

[Didier]

I wrote the J-3 repair Tutorial that Kim hosts on his website. (...) The tutorial is meant to be helpful to those wishing to collimate the lenses for their Leica's, or FSU camera's if need be. It is not an advertisement. Aside from those RFF members that have written to me already, I am not taking in any more lenses for "adjustment".

Hi Brian,

Didn't know you're the author of that very useful repair tutorial. Had jumped over the title with your name and overseen it - sorry! So my sincere thanks go to you!

Tested my replacement Jupiter-3 today again, with a tripod, and found the close focus is quite exactly 5cm behind - this means I need a thicker shim. The actual seems to be 1mm. My two questions (hope I don't bother you):

- Do you know, from your experience, an approx. value how much I should add?
- How can one get such shims without buying a dozen of Ju-3's?

Thanks in advance, Didier

 

[Didier]

Daniel,
many thanks - it works! I tried 80g/m2 paper - focus still slightly behind - 160g/m2 - focus slightly too short. Next step is buying 120g/m2 paper tomorrow!
Cheers,
Didier

 

[hyun5suk]

Hi! everyone. I am new guy here.

I am also trying to collimate my J-3 to Bessa R2A.
Orignal shim in my J-3 has 1.05mm thickness and J-3 showed approx. 5cm behind focus. (Refer to http://www.dantestella.com/technical/compat.html,)

Now I have changed orignal shim to new 1.15mm shim(I made) and I am testing.

I am curious two things.

1. I decided shim thickness for around 1m focus(I have tested 6 thims with 1m target), than What would be happen to infinity focus?

2. After changing shim, F number positin have changed. So I have to mark new red point to see collect F number. What can I do else?

One more question? Is it good idea to use Jupiter-3 or 9 on Bessa R2A?

Thanks lot everybody.

 

[zhang xk]

I would put the lens on a correct body, set the shutter at "B", and use a piece of ground glass, and a big power lope to check the focusing. When the image is sharp, check how much the lens has moved from its corrct position. Then find a proper shim to make it correct. After this, a well made lens should focus at all distances, and if not the lens may have some quality issue like positioning of lens elements, and that would be harder to correct.😀