Leica LTM Diff between LTM & R-LTM

Leica M39 screw mount bodies/lenses
davidnewtonguitars

davidnewtonguitars

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So is there a technical reason that some Russian lenses fit a Leica and some jam half way on?
I know, logically the answer is poor quality control, but is there a technical difference in the thread form?
 
davidnewtonguitars said:
So is there a technical reason that some Russian lenses fit a Leica and some jam half way on?
I know, logically the answer is poor quality control, but is there a technical difference in the thread form?
Click to expand...
Allegedly, it may be that LTM is 39mm x 26 tpi while Russian lenses are 39 x 1 mm (25.4 tpi). Add in tolerances and poor quality control and this may be an answer. But I've never verified it.

Cheers,

R.
 
Hi David,

I'm guessing poor quality control with the Russian lenses (which is well-documented). I have three Leica lenses, from 1936-1939, and they fit my 111c perfectly. I have a 60's 90mm Leica lens which fits my M6 perfectly.

That Leica lenses fit Leica bodies without any problem is also well-documented.

Disclaimer - I don't have a Russian LTM lens to try on my 111c right now.
 
Thanks. I read this somewhere also.
It is very hard to verify because there isn't enough length of thread to measure a cumulative error.

Roger Hicks said:
Allegedly, it may be that LTM is 39mm x 26 tpi while Russian lenses are 39 x 1 mm (25.4 tpi). Add in tolerances and poor quality control and this may be an answer. But I've never verified it.

Cheers,

R.
Click to expand...

So I guess the J-8 isn't going to work on the IIIc, rats!
 
Roger Hicks said:
Allegedly, it may be that LTM is 39mm x 26 tpi while Russian lenses are 39 x 1 mm (25.4 tpi). Add in tolerances and poor quality control and this may be an answer. But I've never verified it.

Cheers,

R.
Click to expand...

Yes, it is the earlier lenses that have a different pitch, as far as I understand it any thing pre war, particularly early Fed. Lots of info in the FSU section.
 
davidnewtonguitars said:
Thanks. I read this somewhere also.
It is very hard to verify because there isn't enough length of thread to measure a cumulative error.

So I guess the J-8 isn't going to work on the IIIc, rats!
Click to expand...

Depends. Is it a very early one, or a later one?

cf.:
The Soviets in the 1930s produced their early FED cameras in M39×1 (39 mm by 1 mm DIN thread).[citation needed] Early Canon cameras also used a different M39 × 24 tpi thread mount,[1] called "J-mount".
Click to expand...
 
I blame it on varying production standards on FSU photo gear.

I have a 1950 KMZ J-12 in LTM that will fit on an 1956 Zorki 4 but not on a 1970s Zorki 4, it will also fit on a Canon III but not a Canon IIF.

The postwar Industar -10 lens also varies a lot from sample to sample in the thread mount, more than the Industar 22 does.

Kiev RF gear with its bayonet mount is also not immune from this lens mount fitting problem on lenses besides the 50 mm ones.

Here I try to match the year of the lens manufacture with a body from around the same time.
 
I have about a dozen of various FSU lenses made ranging from 1953 to 1970s. I have yet to encounter mounting problems with my Canon L2, Canon 7, and/or Bessa-R, which are "Leica Standard" bodies.

Guess I just haven't got enough samples to make it happen.
 
Well my J-8 is a beautiful, almost mint, 1957 sample. Turns out it doesn't mount on the '38 Leica Standard either.
The '52 Industar-22 fits the IIIc fine.
 
Hi,

I was going to sit down with all my ex-USSR lenses and ex-USSR bodies and Leica bodies and then I realised there were 323 (19 x 17) combinations possible.

Add in the Leica lenses and Zenit SLR's and it gets a lot worse.

But I did try putting the oldest lenses on the youngest bodies and the middle aged ones and a few others at random and had one failure when a 30's FED f/2 lens wouldn't fit a 50's body.

Regards, David
 
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My 1956 J-12 would not focus to infinity. I guess quality issues in camera bodies lead to lenses being adjusted to match bodies with flange distance outside tolerance.
 
I had a new Lomo Jupiter 3+ that refused to fully mount on my Leica IIIG, even though it mounted on my other LTM cameras (Leotax S, Canon 7s, Bessa R). After Lomography was kind enough to ship several new lenses at their expense to me, I still could not find one to fit on the IIIG. Oddly, all of my other LTM lenses by Leica, Nikon, Canon, and Cosina Voigtlander fit this camera without a problem.

Finally, Stephen Gandy asked me to send the camera for examination. They found that the camera had taken an imperceptible hit in the past, sufficient to warp the lens mounting flange just enough to prevent the Jupiter 3+ from mounting. The camera body was brought back into alignment, and a new lens mounting flange was installed. Now the Jupiter 3+ mounts with no rough spots or binding.

So, it's not always the Russian lens that's at fault.
 
Robert Lai said:
I had a new Lomo Jupiter 3+ that refused to fully mount on my Leica IIIG, even though it mounted on my other LTM cameras (Leotax S, Canon 7s, Bessa R). After Lomography was kind enough to ship several new lenses at their expense to me, I still could not find one to fit on the IIIG. Oddly, all of my other LTM lenses by Leica, Nikon, Canon, and Cosina Voigtlander fit this camera without a problem.

Finally, Stephen Gandy asked me to send the camera for examination. They found that the camera had taken an imperceptible hit in the past, sufficient to warp the lens mounting flange just enough to prevent the Jupiter 3+ from mounting. The camera body was brought back into alignment, and a new lens mounting flange was installed. Now the Jupiter 3+ mounts with no rough spots or binding.

So, it's not always the Russian lens that's at fault.
Click to expand...
Dear Robert,

A very valid point. Wear and tear is to a considerable extent a sort of post-production quality control, but is often neglected.

Cheers,

R.
 
My Jupiter-3 was a little tight when mounting it on a Leica the first time. But wear and tear seems to have improved that to the point where it goes on any of my LTM leica's without trouble.
The focus is still off, but this is only noticeable wide-open at 1 meter.
 
So a little jeweler's file could be put to use?
<g>

Mr_Flibble said:
My Jupiter-3 was a little tight when mounting it on a Leica the first time. But wear and tear seems to have improved that to the point where it goes on any of my LTM leica's without trouble.
The focus is still off, but this is only noticeable wide-open at 1 meter.
Click to expand...
 
When I was a kid, my desk drawer held several watches that I had taken apart, plus a Praktika SLR that I deconstructed because I wanted to hold a glass pentaprism in my hand.
Today in my shop I have a box heavy with FSU cameras that are apart, in baggies.
I think I've learned my lesson, maybe.

Roger Hicks said:
If you knew what, where and how to file...

Cheers,

R.
Click to expand...
 
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