Using "Normal" M39 Lenses on Soviet M39 Bodies.

[das]

As explained in wonderful detail by folks like Sonnar Brian, we know that Soviet M39 lenses were nearly all made to Contax spec, and not Leica spec. While it seems that the Soviet M39 lenses can be shimmed/adjusted to work well with the Leica M39 standard, what about the reverse? Would Soviet M39 bodies need some kind of modification to work correctly with "regular" Leica spec lenses? Is such a modification actually even practically possible?

 

[Coldkennels]

I can definitively say "yes" on both counts.

I did a quick test a while back: I had a FED 2, Zorki 5 calibrated to Leica spec, and a Leica III to hand, so I thought I'd check how this works. You can see it for yourself quite easily.

First, make sure the FED (or Zorki) is perfectly calibrated for, say, a Jupiter or Industar lens, and your Leica is calibrated for a "true" LTM lens (I used a Summicron in this test). Then set up a test bench - a vertical object with a strong contrasty feature (I have a book that's perfect for this) and a 1m measure. Putting the FED with the film plane at 1m and focusing with the Jupiter should get you a perfect 1m reading; doing the same with the Summicron on a Leica will obviously give the same result.

But swap the lenses over and repeat, and all of a sudden, the distance scale on the lens will give you a different reading when the rangefinder is perfectly aligned at 1m. I just double-checked now, because I couldn't remember which way around it was; a Jupiter on a Leica will read about 1.1m on the distance scale at 1m, while an LTM lens on a FED will either read about 90cm or not be able to make the RF images match at 1m, depending on if your lens will go past 1m close focus or not.

This is easy to "fix", though - you can recalibrate the FED or Zorki to match a Leica lens by spinning the sled-shaped cam follower in the lens mount slightly. That adjusts the close-focus calibration - you'll need to then adjust the infinity, go back and recheck the close-focus, adjust infinity again, and so on until it agrees with a Leica lens at both ends of the scale. It's not hard to do, but it works; that's how I got a Zorki 5 to work perfectly with a Summicron. I actually suspect this may be why FEDs and Zorkis have that teardrop-shaped cam instead of the normal LTM wheel, as it allows you to choose which lenses you want to use. As a result, it's far easier to modify a FED in this way than to get take, for instance, a Canon out of spec to work with unmodified Jupiters.

Of course, the "problem" is that once you've done this, your Jupiters and Industars now behave on the FED or Zorki the same way they do on a Leica. It's obviously reversible, you just have to choose which lens specification is more useful to you. This is why I kept my FED as a "true" FSU body - gives me something to use my Jupiter 3 and Jupiter 9 on without issue.

 

[Ko.Fe.]

It is 100% putting lipstick on the pig.

If you need to put non FSU thread mount RF lenses, just get made in Japan camera, if you don't want to pay for Leica label.

FSU made M39 lenses for first Zenits, btw.

 

[mikeporterinmd]

Through which FSU bodies that this difference from Leica extend? Are all my Jupiter lenses good to go on a FED-1, 2, 4 and Zorki-4? I am only interested in Leica should I happen to buy one. Are there different models of the Jupiters that have different lens registration distances, or all M39 FSU lenses pretty much the same? Excepting any mods made by previous owners.

I am new to FSU and haven't even developed my first rolls of film. Takes a lot longer to shoot 36 frames if you actually have to advance the film 🙂 Excited to see the results and perhaps even do my own developing again. Haven't done that in 40 years or so.

Thanks,

Mike

 

[Coldkennels]

Through which FSU bodies that this difference from Leica extend? Are all my Jupiter lenses good to go on a FED-1, 2, 4 and Zorki-4? I am only interested in Leica should I happen to buy one. Are there different models of the Jupiters that have different lens registration distances, or all M39 FSU lenses pretty much the same? Excepting any mods made by previous owners.

In short, this applies to all FSU LTM cameras and lenses (with, possibly, a few exceptions; I don't know what standard pre-war FED lenses and bodies were made to, and I heard rumours that the Drug might have been made to Leica spec).

Your Jupiters will all work perfectly fine on any FED or Zorki - assuming nothing has been modified, of course. That's the biggest problem with this stuff now; you have no idea what's been tinkered with over the last seventy years and what hasn't.

 

[das]

It is 100% putting lipstick on the pig.

If you need to put non FSU thread mount RF lenses, just get made in Japan camera, if you don't want to pay for Leica label.

FSU made M39 lenses for first Zenits, btw.

Oh, I definitely have more Leica M and Japanese M39 bodies than I know what to do with. 🙂.

 

[das]

I can definitively say "yes" on both counts.

I did a quick test a while back: I had a FED 2, Zorki 5 calibrated to Leica spec, and a Leica III to hand, so I thought I'd check how this works. You can see it for yourself quite easily.

First, make sure the FED (or Zorki) is perfectly calibrated for, say, a Jupiter or Industar lens, and your Leica is calibrated for a "true" LTM lens (I used a Summicron in this test). Then set up a test bench - a vertical object with a strong contrasty feature (I have a book that's perfect for this) and a 1m measure. Putting the FED with the film plane at 1m and focusing with the Jupiter should get you a perfect 1m reading; doing the same with the Summicron on a Leica will obviously give the same result.

But swap the lenses over and repeat, and all of a sudden, the distance scale on the lens will give you a different reading when the rangefinder is perfectly aligned at 1m. I just double-checked now, because I couldn't remember which way around it was; a Jupiter on a Leica will read about 1.1m on the distance scale at 1m, while an LTM lens on a FED will either read about 90cm or not be able to make the RF images match at 1m, depending on if your lens will go past 1m close focus or not.

This is easy to "fix", though - you can recalibrate the FED or Zorki to match a Leica lens by spinning the sled-shaped cam follower in the lens mount slightly. That adjusts the close-focus calibration - you'll need to then adjust the infinity, go back and recheck the close-focus, adjust infinity again, and so on until it agrees with a Leica lens at both ends of the scale. It's not hard to do, but it works; that's how I got a Zorki 5 to work perfectly with a Summicron. I actually suspect this may be why FEDs and Zorkis have that teardrop-shaped cam instead of the normal LTM wheel, as it allows you to choose which lenses you want to use. As a result, it's far easier to modify a FED in this way than to get take, for instance, a Canon out of spec to work with unmodified Jupiters.

Of course, the "problem" is that once you've done this, your Jupiters and Industars now behave on the FED or Zorki the same way they do on a Leica. It's obviously reversible, you just have to choose which lens specification is more useful to you. This is why I kept my FED as a "true" FSU body - gives me something to use my Jupiter 3 and Jupiter 9 on without issue.

Thanks so much for the explanation. This is super interesting. I did not know that the FSU bodies had this capability kind of "built in." Pardon the noob question, but what is the infinity adjustment on FSU bodies? I assume that if the body is calibrated correctly, the rangefinder will not require any further adjusting?

 

[Sonnar Brian]

I've adjusted Nikkor lenses for the Contax RF by reducing the shim. The same is required for using a Leica calibrated lens on the Zorki. Lenses that are over-corrected for spherical aberration will shift towards infinity as they are stopped down. Leave the shim a little thicker than you might.


I adjusted my Zorki 3M with it's great 1x viewfinder to work with my LTM lenses.
BUT- the second problem is the RF Cam follower of the Zorki and Fed will slip under the Cam of some lenses. The Summarit 5cm F1.5 has a thin RF Cam, and will jam on the Zorki.

Jason Howe did a review of the J-3 some years ago, I sent him my PDF instructions for shimming the Jupiter for use on the Leica. I also sent instructions for converting CZJ Sonnars to Leica mount.

https://jasonhowe.blog/aperture-prio...rmation-update

You can also find them Here:

https://learncamerarepair.com/produc...ywords=jupiter

searching for Jupiter.

The Jupiter 5cm lenses have a +/- 1% deviation on focal length. Lenses on the short side of the tolerance are very close to the Leica RF calibration. Those on the far side- might need the rear triplet moved in.

 

[Coldkennels]

Pardon the noob question, but what is the infinity adjustment on FSU bodies? I assume that if the body is calibrated correctly, the rangefinder will not require any further adjusting?

The infinity adjustment is always in roughly the same place, derived from the original Leica II layout - it's hidden behind a screw on the front, somewhere between the two rangefinder windows.

On most FEDs and Zorkis, it's one relatively obvious screw that stands alone and looks a bit out of place. You remove the screw (which is really just covering a hole), and insert a very narrow screwdriver to turn an adjustment screw deep inside the top plate.

On some FEDs and Zorkis it's a bit more hidden; on the Zorki 5 and 6, you need to remove the nameplate, and one of the screws which holds it in place is the one covering the adjustment screw's access hole. On the FED 4 and 5, it's hidden behind the nameplate, which has to be removed by awkwardly pushing it towards the rangefinder window it's next to. If I remember right, on the FED 4, you push it to the right; on the FED 5, you push it to the left. If you manage to push it far enough, it'll pop out and the access hole is then visible - I don't think they have additional covering screws, but it's been a while since I had to tinker with either.

The problem, as mentioned, is that the rangefinder needs tweaking at both ends. If you get the rangefinder to agree with the lens at 1m, then you've thrown infinity out. Adjusting for infinity will throw the close focus out. I remember doing this for the first time with a very badly treated FED 2, and it took me hours to get it right; luckily I had a view over a harbour, and could use a harbour light some miles away as my infinity target while I went back and forth at both ends of the scale until the rangefinder agreed with the lens all the way through the focusing range.

Once you've got the rangefinder dialled in, there should be nothing else to do - unless you hit the cam issues Brian mentioned, anyway. I think some Canon lenses with a partial or "tongue" cam can also cause problems on a FED or Zorki, too.

 

[Ko.Fe.]

The infinity adjustment is always in roughly the same place, derived from the original Leica II layout - it's hidden behind a screw on the front, somewhere between the two rangefinder windows.

On most FEDs and Zorkis, it's one relatively obvious screw that stands alone and looks a bit out of place. You remove the screw (which is really just covering a hole), and insert a very narrow screwdriver to turn an adjustment screw deep inside the top plate.

On some FEDs and Zorkis it's a bit more hidden; on the Zorki 5 and 6, you need to remove the nameplate, and one of the screws which holds it in place is the one covering the adjustment screw's access hole. On the FED 4 and 5, it's hidden behind the nameplate, which has to be removed by awkwardly pushing it towards the rangefinder window it's next to. If I remember right, on the FED 4, you push it to the right; on the FED 5, you push it to the left. If you manage to push it far enough, it'll pop out and the access hole is then visible - I don't think they have additional covering screws, but it's been a while since I had to tinker with either.

The problem, as mentioned, is that the rangefinder needs tweaking at both ends. If you get the rangefinder to agree with the lens at 1m, then you've thrown infinity out. Adjusting for infinity will throw the close focus out. I remember doing this for the first time with a very badly treated FED 2, and it took me hours to get it right; luckily I had a view over a harbour, and could use a harbour light some miles away as my infinity target while I went back and forth at both ends of the scale until the rangefinder agreed with the lens all the way through the focusing range.

Once you've got the rangefinder dialled in, there should be nothing else to do - unless you hit the cam issues Brian mentioned, anyway. I think some Canon lenses with a partial or "tongue" cam can also cause problems on a FED or Zorki, too.

Never had a problem with infinity and vertical adjustments on FSU RF bodies. But I'm native Russian 🙂 .

Thread pitch is different on FSU. You will know it at first attempt to screw in non FSU. It is OK to do it once. But I don't think it is good idea if lens is switched between FSU and else.