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Zorki 4K Jupiter 8 ...Focus issue on Sony E-mount
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PostPosted: Tue Jun 29, 2021 10:50 pm    Post subject: Zorki 4K Jupiter 8 ...Focus issue on Sony E-mount Reply with quote
Today I bought a Zorki 4K complete with a beautiful Jupiter 8 50mm F2 lens

The lens focus ring moves sweetly and the aperture opens and closes perfectly

I was excited as I love shooting portraits and I was keen to try it out

When I attached it to my Sony A6000 using a L39 to E-mount adapter I have some focus issues

The nearest I can focus is when the subject is about 3 metres away from the camera and I get to infinity focus when the distance on the lens is about 4 metres. This means I cannot use the lens as I want to.

The adapter works fine for my Industar N61 lenses and my Dad's 1950's leica lenses.

I thought it might need an M42-L39 spacer, but that wont focus anywhere !

Btw the focus ring moves all the way through the scale .

Am I missing a trick? Can anyone help me with a solution to this issue

Many Thanks

#1


PostPosted: Wed Jun 30, 2021 9:36 am    Post subject: Reply with quote
Do I need an m39 adapter as opposed to a L39 adapter . I have been browsing various geek forums .

I thought they were the same


PostPosted: Wed Jun 30, 2021 11:29 am    Post subject: Reply with quote
Take a look at this guide. You may need to add a shim below the optical block as show on the middle of the 2nd photo.

https://yukosteel.wordpress.com/2019/03/09/mod-jupiter-8-50mm-f2-0-focus-to-0-6m/


PostPosted: Wed Jun 30, 2021 11:35 am    Post subject: Reply with quote
It's probably the lens, not the adapter that is the problem. Does it overshoot infinity?


PostPosted: Wed Jun 30, 2021 11:52 am    Post subject: Reply with quote
D1N0 wrote:
It's probably the lens, not the adapter that is the problem. Does it overshoot infinity?


Thanks ,

Yes infinity focus is half way on the focus ring , if I turn the ring to infinity it is out of focus


PostPosted: Wed Jun 30, 2021 11:53 am    Post subject: Reply with quote
calvin83 wrote:
Take a look at this guide. You may need to add a shim below the optical block as show on the middle of the 2nd photo.

https://yukosteel.wordpress.com/2019/03/09/mod-jupiter-8-50mm-f2-0-focus-to-0-6m/

Thanks for the link

Wow this is outside my comfort zone .

So will M39 as opposed to L39 work ?


PostPosted: Wed Jun 30, 2021 12:58 pm    Post subject: Reply with quote
m39 and l39 is the same (apart from early Zenit SLR M39, but the Jupiter 8 is a rangefinder lens, so that is not the case). You could try to use a short extension tube for closer focussing if you are not comfortable opening the lens up. Another technique I use with longer close focussing distances and screw mount lenses is turning the lens out of the thread as far as I dare and focus by moving the camera.

There is probably a problem with infinity adjustment due to somebody servicing the lens without really knowing what they were doing.


PostPosted: Wed Jun 30, 2021 1:58 pm    Post subject: Reply with quote
How's the focus range on the Zorki? Smile


PostPosted: Wed Jun 30, 2021 3:38 pm    Post subject: Reply with quote
bwfcnottingham wrote:
D1N0 wrote:
It's probably the lens, not the adapter that is the problem. Does it overshoot infinity?


Thanks ,

Yes infinity focus is half way on the focus ring , if I turn the ring to infinity it is out of focus

You only need to do step 1....


PostPosted: Wed Jun 30, 2021 6:16 pm    Post subject: Re: Zorki 4K Jupiter 8 ...Focus issue on Sony E-mount Reply with quote
bwfcnottingham wrote:
Today I bought a Zorki 4K complete with a beautiful Jupiter 8 50mm F2 lens

The lens focus ring moves sweetly and the aperture opens and closes perfectly

I was excited as I love shooting portraits and I was keen to try it out

When I attached it to my Sony A6000 using a L39 to E-mount adapter I have some focus issues

The nearest I can focus is when the subject is about 3 metres away from the camera and I get to infinity focus when the distance on the lens is about 4 metres. This means I cannot use the lens as I want to.

When you notice the focus range shifted toward the camera, it's a sign the optics is too far from the focal plane.
When the focus range is shifted towards infinity, it's a sign the optics are too close to the focal plane.

If the image quality is good, it's likely that the lens needs shims to correctly calibrate or offset the optics to where they need to be.
Set the lens to infinity, measure the length of the lens, then set the focus so infinity is sharp, measure the lens length again.
Subtract the two measurements and this will tell you how thick the shim needs to be.
You can order a shim from RAF camera, all you need is 3 measurements I.D., O.D., and thickness, some kind soul could measure the I.D. and O.D. of the shim from their lens.
Test fit the new shim to see how close infinity is, falling short of infinity is a good thing, it means the shim is slightly too thick, all you need to do is sand the side a bit with 600-800 grit sandpaper and frequently test for infinity focus.

Quote:

The adapter works fine for my Industar N61 lenses and my Dad's 1950's leica lenses.

I thought it might need an M42-L39 spacer, but that wont focus anywhere !

Nope, looks to me it needs a shim, either in the lens(the proper place to shim so that the lens will be correct on any LTM adapter.
You could shim the adapter if it's a 2 piece adapter but the lens will require the adapter to be permanently mounted, the adapter will only be useful with this lens.

Quote:

Btw the focus ring moves all the way through the scale .

Am I missing a trick? Can anyone help me with a solution to this issue.

Many Thanks

You could make a shim, or buy a donor lens and use its shim.


PostPosted: Wed Jun 30, 2021 7:04 pm    Post subject: Reply with quote
visualopsins wrote:
How's the focus range on the Zorki? Smile


Hi visualopsins, the lens on the zorki focusses ok , right up to 1 metre and infinity. What does that mean ?


PostPosted: Wed Jun 30, 2021 7:08 pm    Post subject: Reply with quote
I am interested in the results of your investigtion, as it may shed light on a similarly mysterious behaviour of Voigtlander lenses on DKL adapter I experimented.


PostPosted: Wed Jun 30, 2021 7:19 pm    Post subject: Re: Zorki 4K Jupiter 8 ...Focus issue on Sony E-mount Reply with quote
[/quote]
You could make a shim, or buy a donor lens and use its shim.[/quote]

AHH right this is getting quite technical and geeky . I've only took apart two lenses . A beautiful CZ Jenna 135 mm that I thought needed lubricating and ended up breaking the aperture pin mechanism and a Pentax 135mm SMC that is still in bits ,I need to put the aperture return spring back on , so my track record isn't proven !!!


PostPosted: Wed Jun 30, 2021 7:53 pm    Post subject: Reply with quote
bwfcnottingham wrote:
visualopsins wrote:
How's the focus range on the Zorki? Smile


Hi visualopsins, the lens on the zorki focusses ok , right up to 1 metre and infinity. What does that mean ?


The need to duplicate the Zorki camera register distance, from rear of mount to film plane, with the adapter used when mounting lens on Sony A6000 -- this will enable lens use on both Zorki and on A6000. I can't find distance for Zorki. Anybody know? You can perhaps measure it carefully -- remove lens, open shutter, measure from front of lens mount to film plane. Subtracting Sony A6000 register distance from that distance gives how thick must be the adapter...

(I'm not a fan of modifying lens adjustments to "make it work" on another camera. Smile)

Last edited by visualopsins on Thu Jul 01, 2021 6:42 am; edited 1 time in total


PostPosted: Thu Jul 01, 2021 3:45 am    Post subject: Reply with quote
bwfcnottingham wrote:
visualopsins wrote:
How's the focus range on the Zorki? Smile


Hi visualopsins, the lens on the zorki focusses ok , right up to 1 metre and infinity. What does that mean ?

Well, that changes things, it doesn't work right on the adapter that other lenses do work correctly on, and it works fine on the Zorki... honestly that's bizarre, does the other lenses work as they should on the Zorki?
I'm beginning to think the lens was adjusted to work on that body, which means a dedicated adapter that is modified to work with the lens, or go find another J8, this is my recommendation.


PostPosted: Thu Jul 01, 2021 8:47 am    Post subject: Reply with quote
visualopsins wrote:
I can't find distance for Zorki. Anybody know?

28.8mm, exactly the same as for LTM/L39

bwfcnottingham wrote:
the lens on the zorki focusses ok , right up to 1 metre and infinity

How did you check this? With just the rangefinder (which may be thrown off on the lens side) or directly at the film plane?


PostPosted: Thu Jul 01, 2021 11:26 am    Post subject: Reply with quote
Alex TG wrote:
visualopsins wrote:
I can't find distance for Zorki. Anybody know?

28.8mm, exactly the same as for LTM/L39

bwfcnottingham wrote:
the lens on the zorki focusses ok , right up to 1 metre and infinity

How did you check this? With just the rangefinder (which may be thrown off on the lens side) or directly at the film plane?


All

I thought the Jupiter was focussing ok on the zorki , but when I put my industar n61 on the zorki it focusses much more sharper and clearer so I conclude the Jupiter 8 isn't right .

Thanks for all the advice ,dunno wot to do next


PostPosted: Thu Jul 01, 2021 11:53 am    Post subject: Reply with quote
I've just tried my Jupiter 8, taken off a Zorki 4K, on my A7II using a M39 adapter and it works perfectly. The adapter is 10.7 mm between the Sony lens mount face and the rear face of the Jupiter.


PostPosted: Thu Jul 01, 2021 1:33 pm    Post subject: Reply with quote
Lightshow wrote:
bwfcnottingham wrote:
visualopsins wrote:
How's the focus range on the Zorki? Smile


Hi visualopsins, the lens on the zorki focusses ok , right up to 1 metre and infinity. What does that mean ?

Well, that changes things, it doesn't work right on the adapter that other lenses do work correctly on, and it works fine on the Zorki... honestly that's bizarre, does the other lenses work as they should on the Zorki?
I'm beginning to think the lens was adjusted to work on that body, which means a dedicated adapter that is modified to work with the lens, or go find another J8, this is my recommendation.


Lightshow see my earlier comment I thought the Jupiter was focussing ok on the zorki ( I have 60 something year old eyes ) but my industar n61 on the zorki is pin sharp throughout the focus range , which I guess means the Jupiter is broken / no good . I should have tried to focus it in the shop through the zorki but was seduced by the smooth focus ring and aperture . A £35 error on my behalf , although I have a cool looking camera for my vintage lens shelf 📷📷


PostPosted: Thu Jul 01, 2021 1:55 pm    Post subject: Reply with quote
I just separated the lens , it's like a jam jar , yo twist the focus ring one way and the aperture ring the other way and you get access to the inside . There was a shim ring inside . I removed it and focussed again . This time infinity was reached at 1m on the ring . I assume if I get some more rings it will sort itself out . Any ideas where I can get some


PostPosted: Thu Jul 01, 2021 3:57 pm    Post subject: Reply with quote
I suggest you try to match the spacer to a filter, then look for fiilters that have a screw on part holding the glass in place, Amazon basics were like that, Then take the glass out of a filter and see how it goes in to the jam jar and sits with the spacer. If you need a lot it may be expensive, But at least filters are Black, you don't want anything shiney

In any case the filter size will give you a good idea of what else to look at.


PostPosted: Thu Jul 01, 2021 4:47 pm    Post subject: Reply with quote
Maybe some black rubber o-ring(s) will work. They are available in many sizes and cheap.


PostPosted: Thu Jul 01, 2021 6:38 pm    Post subject: Reply with quote
bwfcnottingham wrote:
I just separated the lens , it's like a jam jar , yo twist the focus ring one way and the aperture ring the other way and you get access to the inside . There was a shim ring inside . I removed it and focussed again . This time infinity was reached at 1m on the ring . I assume if I get some more rings it will sort itself out . Any ideas where I can get some

Take the little shim ring to a machine shop and see what they can come up with for making a few of them at different thicknesses, at the very least you can use the ring as a template and cut out some pop cans into squares, drill the centres or cut with an Xacto blade, cut them round and remove any burrs then bolt them together and file the outside diameter, you could chuck the bolt in a drill to speed up the process.


PostPosted: Fri Jul 02, 2021 7:11 am    Post subject: Reply with quote
D1N0 wrote:
Maybe some black rubber o-ring(s) will work. They are available in many sizes and cheap.


Thank you everyone for your help and advice . The response to my call for help has been fabulous.

Once I get it fixed , I will post some photos . Thanks again everyone 😊📷


PostPosted: Sun Jul 04, 2021 11:41 pm    Post subject: (RESOLVED) Zorki 4K Jupiter 8 ...Focus issue on Sony E-mount Reply with quote
Hi All

I managed to fix my focus issues

I went to a couple of hardware shops, lens and little spacer in hand.

Neither shop could find a suitable ring, so I was disappointed.

I decided to ask my neighbour, a retired engineer, if he knew anywhere that could supply one.

Dave said he could try to make one for me on his lathe and took the little spacer away with him.

He returned about 10 minutes later, he'd printed one on his 3D printer !

It didn't quite fit as the edges were a little rough

He returned 15 minutes later with three and we placed a couple into the lens.

Hey presto it worked ! Well when I say worked, it can close focus OK and focus to infinity too, although infinity is a bit before the infinity marker on the lens barrel. I think I can faff around with the three spaces and the original to get a perfect fit.

Here's a photo of Dave, Sony A6000 and fairly wide open aperture
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