Jupiter-8 and Zorki Rangefinder issue

[sepha.kay]

I have recently purchased a serviced Zorki 1-C and did a full CLA on it. Everything functions perfectly. I even properly adjusted the flange distance to 28.8mm +/- 0.02mm, but the only thing left to fix is the RF, which I am having problems with. I am currently using a 1963 Jupiter-8 from my previous Zorki 4 camera to calibrate the RF.



I have done this with 3 other Zorki cameras in the past with the same lens (Jupiter-8) and the 1M adjustment never lines up with the 1M mark on the lens after fixing the infinity. It is usually off by 1.50-2mm from the 1M mark, but never under 0.50mm or spot on.



The camera was serviced before I purchased it, so I shot a roll or two before I started the CLA just to check. The results were sharp at close distance and far. However, the lens was still off by a few millimeters from the 1M mark like always. I believe the incorrect flange distance made up for incorrect RF at the time, so that ended up giving me sharp results. Now that I corrected flange distance during the CLA, the lens and RF will make a negative impact on my photos, especially shooting at wide open.


What might be the reason behind this? Am I doing something wrong, is it the lens, or the camera? If it is the lens, any way to fix it? :bang:

 

[Ko.Fe.]

Camera focuses right? Why it is a problem?
All of my FSU and almost all old LTM lenses will go little bit more after 1m mark.

 

[wolves3012]

There's a thread in the repair forum on rangefinder adjustment, it used to be in the FSU section but has been moved to:

https://www.rangefinderforum.com/forums/showthread.php?t=73900

I'm not qute sure I follow your problem, if it's the lens or body. Have you adjusted the RF at BOTH ends (infinity and 1m)? You really need to establish if the body or the lens is the problem. If you shoot a frame with a subject at exactly 1m and the lens set to exactly 1m, is it sharp? If it is, the body is not adjusted properly, if the RF doesn't agree.

 

[sepha.kay]

Camera focuses right? Why it is a problem?
All of my FSU and almost all old LTM lenses will go little bit more after 1m mark.

Well, the thing is it shouldn't. It is supposed to be right on the 1M line. Infinity first, then RF coupler alteration until the lens and RF both agree at 1M, then repeat until both are on point.



After hundreds of attempts, same result. A friend of mine has a J8 too and his lens lines up with the 1M and infinity. Mines always off a few millimeters and that can really make a difference in a photo.

 

[sepha.kay]

There's a thread in the repair forum on rangefinder adjustment, it used to be in the FSU section but has been moved to:

https://www.rangefinderforum.com/forums/showthread.php?t=73900

I'm not qute sure I follow your problem, if it's the lens or body. Have you adjusted the RF at BOTH ends (infinity and 1m)? You really need to establish if the body or the lens is the problem. If you shoot a frame with a subject at exactly 1m and the lens set to exactly 1m, is it sharp? If it is, the body is not adjusted properly (or the lens' own scale isn't).

I am 100% sure that I am calibrating the RF correctly. Infinity first, then RF coupler alteration until 1M agrees, then back to infinity again, so on so on. I am also certain that it is not the body because I stated that I have done this with 3 other Zorki cameras and I get the same results. The lens on the other hand seems to function correctly. Smooth focus ring, smooth aperture ring, clean glass, etc etc. It just wont align with the 1M like it is supposed to.

 

[wolves3012]

Well, the thing is it shouldn't. It is supposed to be right on the 1M line. Infinity first, then RF coupler alteration until the lens and RF both agree at 1M, then repeat until both are on point.



After hundreds of attempts, same result. A friend of mine has a J8 too and his lens lines up with the 1M and infinity. Mines always off a few millimeters and that can really make a difference in a photo.

I don't think you two are talking about the same thing. Most FSU lenses only go to 1m on the scale but they can be turned slightly past that mark. Are you saying this is what bothers you? Or do you mean the lens scale doesn't read 1m when it really is focussed properly on a 1m subject and the photo IS sharp?

 

[wolves3012]

I am 100% sure that I am calibrating the RF correctly. Infinity first, then RF coupler alteration until 1M agrees, then back to infinity again, so on so on. I am also certain that it is not the body because I stated that I have done this with 3 other Zorki cameras and I get the same results. The lens on the other hand seems to function correctly. Smooth focus ring, smooth aperture ring, clean glass, etc etc. It just wont align with the 1M like it is supposed to.

It's possible on most FSU lenses to move the scale around (tiny screws set into the ring hold it place), so you could move it so that 1m shows correctly. BUT you might then find the infinity mark is wrong. It's possible you may just have to live with one or other end wrong. Assuming the lens is actually focussed properly on what the RF says it is, the scale is just an "indication" and not deadly accurate. Have you tried ther lenses or is it just on this one?

 

[sepha.kay]

I don't think you two are talking about the same thing. Most FSU lenses only go to 1m on the scale but they can be turned slightly past that mark. Are you saying this is what bothers you? Or do you mean the lens scale doesn't read 1m when it really is focussed properly on a 1m subject and the photo IS sharp?

It is not on the 1M mark, but the RF reads it as 1M. It sits a few millimeters to the right. Not past the 1M where the focus ring stops turning, but closer to 1.2M.



You see, if the flange is corrected and the RF reads the lens is at 1M, but its not actually on the 1M, the results will be out of focus.

 

[sepha.kay]

It's possible on most FSU lenses to move the scale around (tiny screws set into the ring hold it place), so you could move it so that 1m shows correctly. BUT you might then find the infinity mark is wrong. It's possible you may just have to live with one or other end wrong. Assuming the lens is actually focussed properly on what the RF says it is, the scale is just an "indication" and not deadly accurate. Have you tried ther lenses or is it just on this one?

I'm not sure what you are referring to as the "tiny screw set to move around the scale"?


Yes, I have a I-22, but it reads wrong once I place the lens on the body I just calibrated with the J8. Then once I calibrate the I-22, the J8's reading are way off?

 

[wolves3012]

I'm not sure what you are referring to as the "tiny screw set to move around the scale"?


Yes, I have a I-22, but it reads wrong once I place the lens on the body I just calibrated with the J8. Then once I calibrate the I-22, the J8's reading are way off?

On the Jupiter 8 there are screws (3 of them, I think) in the ring that is the moving part that you turn to focus. They can be loosened slightly to move the ring - DO NOT take them out since they are really tiny and easily lost.

However, I'm not convinced this is the answer here. Assuming the lens is actually correctly focussed at 1m when the scale says it is, the body has to be wrong (for that lens anyway). Let's double-check you really did do the RF alignment correctly: First set the lens to infinity. Adjust the RF infinity screw so that the RF agrees. Now set the lens to 1m and place a target 1m in front of the camera film-plane. Adjust the sensor-tip until the RF agrees. Repeat these two until both ends agree.

Assuming this is what you did, the lens now WILL be on 1m at 1m and not off at all, it cannot be otherwise. In my experience, there is always a small error from one lens to another, so you will not achieve perfection across a range of lenses but they should be pretty close.

 

[sepha.kay]

On the Jupiter 8 there are screws (3 of them, I think) in the ring that is the moving part that you turn to focus. They can be loosened slightly to move the ring - DO NOT take them out since they are really tiny and easily lost.

However, I'm not convinced this is the answer here. Assuming the lens is actually correctly focussed at 1m when the scale says it is, the body has to be wrong (for that lens anyway). Let's double-check you really did do the RF alignment correctly: First set the lens to infinity. Adjust the RF infinity screw so that the RF agrees. Now set the lens to 1m and place a target 1m in front of the camera film-plane. Adjust the sensor-tip until the RF agrees. Repeat these two until both ends agree.

Assuming this is what you did, the lens now WILL be on 1m at 1m and not off at all, it cannot be otherwise. In my experience, there is always a small error from one lens to another, so you will not achieve perfection across a range of lenses but they should be pretty close.

If I were to do that then it would still be out of focus still, but read 1M..?



On the other hand, the way you described the RF calibration method is the exact way I do mine. I have no doubt.



I guess either I keep calibrating until finally stops at 1M (doubt), or get a new lens... unless there is a way to fix the lens...

 

[wolves3012]

If I were to do that then it would still be out of focus still, but read 1M..?

Yes, that's possible. You really need to know if the lens focusses at 1m when the scale says 1m. If that's true, the lens is not at fault in an optical sense, but the cam could still be the problem, or the lens shim incorrectly set.

On the other hand, the way you described the RF calibration method is the exact way I do mine. I have no doubt.

The bit where I'm confused is that you say you have calibrated the RF at 1m but the lens scale doesn't agree. If you set the lens scale to 1m first, how can it be at anything else afterwards?

I guess either I keep calibrating until finally stops at 1M (doubt), or get a new lens... unless there is a way to fix the lens...

You really need to find which part of the equation is wrong before you can fix it. Is the body out of calibration? Is the lens optically correct? Is the lens cam correct? Until you know which of these is wrong you cannot put it right.


P.S. I hope this is not coming across as being confrontational or argumentative because that's not what I intend, I'm just trying to understand where the problem lies and help out.

 

[sepha.kay]

Yes, that's possible. You really need to know if the lens focusses at 1m when the scale says 1m. If that's true, the lens is not at fault in an optical sense, but the cam could still be the problem, or the lens shim incorrectly set.


The bit where I'm confused is that you say you have calibrated the RF at 1m but the lens scale doesn't agree. If you set the lens scale to 1m first, how can it be at anything else afterwards?




You really need to find which part of the equation is wrong before you can fix it. Is the body out of calibration? Is the lens optically correct? Is the lens cam correct? Until you know which of these is wrong you cannot put it right.


P.S. I hope this is not coming across as being confrontational or argumentative because that's not what I intend, I'm just trying to understand where the problem lies and help out.

My apologies for the misunderstanding. What I am trying to say is that I can never get it to land on the 1M while calibrating the RF. Its eventually supposed to land on both infinity and 1M, right? But its only infinity and never on the 1M line. Always off to the side no matter what I do. Every time I always end up in the same configuration.


Here is a picture for example.

 

[wolves3012]

Ok, I see what you mean. It *should* be possible to get the RF to line up correctly at 1m and infinity but that photo shows it to be very close. Ok, not perfect but close. If you look at the depth-of-field scale, you're within the f/2 markings at that setting, so even wide-open close-up should be OK. Frankly, if I couldn't get better than that I'd live with it. The real test is whether a close-up shot is focussed acceptably on the film.

By the way, it might be better to accept an error at the infinity end if that allows close-focus to be exact. Depth-of-field is more likely to cover an error there because there's more of it (DOF). The crunch test is still actual performance with film, of course.

EDIT: I've gone through this on many FSU cameras and lenses. They were not made to tight tolerances and I often had to compromise, luck plays a part. You can set one lens up perfectly, then change to another and find it's close but not exact. Other bodies may hold up fine over several lenses - or not!

 

[Ko.Fe.]

I cheked Z4K with J-8 and it does 1M on the lens and RF.

If I remember correct, it depends how multi-thread focus heliciod was reassembled.
Or your lens is Moday shift lens.

If it does the same on all bodies.

I have done this with 3 other Zorki cameras in the past with the same lens (Jupiter-8) and the 1M adjustment never lines up with the 1M mark on the lens after fixing the infinity. It is usually off by 1.50-2mm from the 1M mark, but never under 0.50mm or spot on.

UPD: I shifted J-8 focus as on the picture. According to the ruler it didn't made any significant difference in the distance.

 

[Brambling]

I cheked...

I fully agree with the previous speaker and follow the topic with great excitement. 🙄

 

[sepha.kay]

Ok, I see what you mean. It *should* be possible to get the RF to line up correctly at 1m and infinity but that photo shows it to be very close. Ok, not perfect but close. If you look at the depth-of-field scale, you're within the f/2 markings at that setting, so even wide-open close-up should be OK. Frankly, if I couldn't get better than that I'd live with it. The real test is whether a close-up shot is focussed acceptably on the film.

By the way, it might be better to accept an error at the infinity end if that allows close-focus to be exact. Depth-of-field is more likely to cover an error there because there's more of it (DOF). The crunch test is still actual performance with film, of course.

EDIT: I've gone through this on many FSU cameras and lenses. They were not made to tight tolerances and I often had to compromise, luck plays a part. You can set one lens up perfectly, then change to another and find it's close but not exact. Other bodies may hold up fine over several lenses - or not!

I cheked Z4K with J-8 and it does 1M on the lens and RF.

If I remember correct, it depends how multi-thread focus heliciod was reassembled.
Or your lens is Moday shift lens.

If it does the same on all bodies.



UPD: I shifted J-8 focus as on the picture. According to the ruler it didn't made any significant difference in the distance.

I managed to finally get them both aligned. What a relief! 🙂 Not sure what the issue was before, but It worked after a few attempts. I'm glad my lens didn't turn out to be faulty either. Thanks to everyone who helped! 😱