L39 vs M39...What's the difference?

M39 = 39mm diameter thread mount. There are two major variants, M39 LTM (Leica rangefinder) and M39 Zenit (SLR). They two are distinguished by the registration distance of the mount face to the film plane.

L39 = M39 LTM

LTM = M39 LTM

LSM (Leica Screw Mount) = LTM

Throw in enlarger lenses and various non-standard registrations and there is quite a menagerie. For more information see the not-quite-accurate article in the Wikipedia.


Steve
 
Steve sumarizes it perfectly. To add to the fun, the Leica thread is 26 tpi but reportedly some manufacturers used 1mm, i.e. 25.4 tpi. Depending on how sloppy the male and female threads are, these may or may not interchange, or may just be tight. Then there's thread angle...

Cheers,

R.
 
As Steve already mentioned above, the early Zenit SLRs (Zenit, Zenit-C, Zenit E, etc.) had M39 threads too, and to distinguish it from the rangefinder M39 sometimes one just call it ZM39. (Btw. the M stands for the metric screw thread and is followed by the value of the nominal diameter in millimetres.)
 
My two cents, if you mount a LTM 39 lens on a Zenit camera (or a Zorki/Fed rangefinder lens) you get a Macro lens. LTM 39 will never focus to infinity on a M39 SLR (Zenit 3M, Kristal, Zenit, Zenit 3 or Start with the adapterring).

The other way around won't work either 🙂

Having said that, I made great macroshots with a J8 in LTM 39 on my Zenit 3m 🙂
 
stevebrot said:
It is my understanding that the Zenit lenses can be adapted with loss of rangefinder coupling...but who would want to 🙂
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Well, the LTM non-collapsible Industar 50 is just the Z39 I-50 on an extension ring. I've got one lying around that I'm planning on taking apart at some point to explore how that works, but I have no other Z39 lenses to play with.

Is there a Z39 wide-angle? If so, you could probably give that a try on an extension ring, rangefinder coupling or not.
 
I started this thread because of all the different descriptions I was seeing on LTM lenses for sale. And the fact that my I-26M wouldn't fit my Zorki 1 at first, making me think that it had some kind of thread mis-match. I knew about the difference in lens-to-film plane register, but not about the fact that early Zorki's had a different mount than the later ones. Mine is a later model, so I figured one Industar should be the same as another. It could be it just had a bad spot in the thread, but I wanted to make sure I wasn't getting into a big snafu with varying lens mounts.

I have a couple of Zenits, but they are both M42 thank goodness. Neither is operational, so if I want to use the lenses, its back to digging out the Ricoh's. And I plan on keeping my Zorki all FSU. Unless I get an Amedeo Adapter.

PF
 
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Coldkennels said:
Well, the LTM non-collapsible Industar 50 is just the Z39 I-50 on an extension ring. I've got one lying around that I'm planning on taking apart at some point to explore how that works, but I have no other Z39 lenses to play with.

Is there a Z39 wide-angle? If so, you could probably give that a try on an extension ring, rangefinder coupling or not.
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I've tried removing the extension ring from an Industar 50, I gave up after find it is incredibly tight and I didn't want to break things in the attempt - more so as I have a couple of them in Z39 anyway.

The commonest wideangle in Z39 is the MIR-1, which is a prize-winning 37mm f/2.8 (it won the Grand Prix Bruxelles 1958 and is usually engraved to say so)
 
farlymac said:
I started this thread because of all the different descriptions I was seeing on LTM lenses for sale. And the fact that my I-26M wouldn't fit my Zorki 1 at first, making me think that it had some kind of thread mis-match. I knew about the difference in lens-to-film plane register, but not about the fact that early Zorki's had a different mount than the later ones. Mine is a later model, so I figured one Industar should the same as another. It could be it just had a bad spot in the thread, but I wanted to make sure I wasn't getting into a big snafu with varying lens mounts.

I have a couple of Zenits, but they are both M42 thank goodness. Neither is operational, so if I want to use the lenses, its back to digging out the Ricoh's. And I plan on keeping my Zorki all FSU. Unless I get an Amedeo Adapter.

PF
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I'm not too sure about the early Zorkis being different, Jay Javier would know (ZorkiKat on here). The I-61 *ought* to fit without problems on yours but I have one I-61 that the thread sticks a bit too. Maybe they weren't too hot on machining the threads on them.
 
Okay, this brings up another question, "How to tell a Z39 lens from an M39", or "What lenses are Z39 mount?". Because I'm considering getting a Zenit-C (S), and don't want to get into a big hassle with finding other focal lengths for it. (This is just some forward thinking on my part, please don't offer me any cameras/lenses as I'm not buying right now.)

PF
 
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farlymac said:
Okay, this brings up another question, "How to tell a Z39 lens from an M39", or "What lenses are Z39 mount?". Because I'm considering getting a Zenit-C (S), and don't want to get into a big hassle with finding other focal lengths for it. (This is just some forward thinking on my part, please don't offer me any cameras/lenses as I'm not buying right now.)

PF
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Simplest way to tell is the lack of RF coupling cam. Saying that, I think the L39 Russar 20mm has no cam so it's not a guaranteed way. Take a look at the Jupiter 11, however and the RF and SLR varieties are quite different. A pre-set ring is also a giveaway, no RF lens would have that. Other than that, do your homework on any likely purchases and ask the seller if they're sure which type it is. The Industar 50 is a far smaller mount, for instance, in Z39 - much shorter and easy to tell from the L39 version. It's what usually comes on the Zenit C.

Common lenses for the Z39 are the Industar 50, the Jupiter 11 (135mm f/4) and the MIR-1 I've mentioned above (there's no RF version of that). I think the Jupiter 8 may also have been made in Z39, not sure.
 
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edit: wolves3012 got it! 🙂

"What lenses are Z39 mount?": Well, I do not know all the lenses which were ever made, but here are some:

Mir-10A, Mir-1, Mir-1A, Industar-22, Industar-50, Helios-44, Helios-44-2, Helios-40-2, Jupiter-9, Vega-13A, Jupiter-11, Jupiter-11A, Tair-11, Tair-11A, Jupiter-6, Telemar-22, Tair-3, MTO-500

Rare, scarce lenses: , Industar-26M, Vega-1, Industar-24M, Jupiter-21

(I've seen a ZM39 Revue 3,5/135 too.) 🙂
 
26tpi was the old (?1890's) Royal Microscope Society standard for microscopes (there's a link there with Leica pre-cameras). I'm told that after a Japanese firm made some to not-quite-that they designed a hybrid thread that worked with both and used it, and some then copied them. It might be true and explain a lot of things.

I can't find my notes on this, so its from memory; sorry. The gentleman I spoke to is generally acknowledged to be the expert on Leicas.

Regards, David
 
Thanks to Wolves3012 and Veloman, I now have my search list made out. I never thought about checking for the cam. Of course, if there are more lenses out there not mentioned above, feel free to add to the list.

Thanks Everyone,

PF
 
farlymac said:
Thanks to Wolves3012 and Veloman, I now have my search list made out. I never thought about checking for the cam. Of course, if there are more lenses out there not mentioned above, feel free to add to the list.

Thanks Everyone,

PF
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PM me if/when you want a Zenit C, I have a boxed, working one in VGC that I'd part with for a sensible price. I'm just not using it enough to keep it...plus I can't focus close enough these days without glasses - the clever designers put the screen rather close, optically! 😡
 
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