How to use M-mount lenses with old LTM cameras?

[rivi1969]

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Good evening,

I have seen some interesting old rangefinder cameras with LTM mount, however I couldn't find any adapter to fit M-mount lenses on those old bodies, there are thousands to adapt LTM lenses to M-mount bodies but not the other way around, so maybe there isn’t even possible?

Thank you!

Ricardo

[LocalHero1953]

The LTM bodies have a shorter 'registration distance' (distance from mount to film) than M mount bodies, so even if you could physically mount a M lens, it wouldn't focus to infinity, and the rangefinder would not be properly calibrated. I'm sure the M mount was designed that way so LTM lenses would all fit on the new M bodies at launch.  

[mmradman]

LTM lens can be used on M camera via adapter but not other way round, the LTM lens have longer register distance by 1mm.

Leica LTM = 28.8mm

Leica M = 27.8mm

https://en.wikipedia.org/wiki/Flange_focal_distance

[a.noctilux]

As rule of thumb,

when one mount "A" can be adapted to "B" as "A to B adapter", in general, there is no "B to A" adapters.

 

Of course we can find some exceptions.

I can put M lenses on my BEOON ( more here ) and use screw mount Leica but only in close range or copying.

[Infantasy]

The RF on LTM lens will only accurate if you use an exact 1mm adapter. So I have hesitation on precise focusing and therefore I only use M lens so far.

[pippy]

1 hour ago, Infantasy said:

The RF on LTM lens will only accurate if you use an exact 1mm adapter. So I have hesitation on precise focusing and therefore I only use M lens so far.

There's no need to hesitate.

As Paul mentioned in post #2; right from the beginning the M camera system was designed specifically to be able to match perfectly with Leica's screw-mount lenses by using an LTM-to-M adapter. Get a decent quality adapter and there is no focussing issue as far as RF calibration is concerned.

Philip.

Edited October 5, 2021 by pippy

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vor 14 Minuten schrieb pippy:

no focussing issue as far as RF calibration is concerned

Given the way the lens couples to the RF, you'd have no issues regardless of the thickness of the adapter. You couldn't reach infinity if the adapter was too thick, and the scale on the lens would be off, but the RF would work with an old LTM lens.

[spydrxx]

LTM lenses work on M bodies using an adapter but M lenses don’t work on LTM bodies due to registration differences which can’t be compensated for and still provide infinity focus. This applies to lenses in a fixed mount. Some M mount lenses have a removable head for use in a Visoflex and can be used with LTM bodies if the Visoflex has the proper rear mount…as far as I know the lenses in question start at 65mm and longer focal lengths, no shorter focal lengths.

[sf_photo]

12 hours ago, rivi1969 said:

Good evening,

I have seen some interesting old rangefinder cameras with LTM mount, however I couldn't find any adapter to fit M-mount lenses on those old bodies, there are thousands to adapt LTM lenses to M-mount bodies but not the other way around, so maybe there isn’t even possible?

Thank you!

Ricardo

I think your best bet for good glass for a LTM camera is to purchase Voigtlander LTM lenses, they have made several in past years. Leitz also made some dual mount lenses: one backs off a setscrew and the M type mount unscrews revealing an LTM. Not many though and all older and chrome finish. One I have had: 21f4, 35f3.8, 35f2

[LocalHero1953]

IIRC I had a chrome Summaron 35/2.8 which was basically a LTM mount lens with an adapter permanently fixed to it.  

[Guest]

vor 9 Minuten schrieb LocalHero1953:

IIRC I had a chrome Summaron 35/2.8 which was basically a LTM mount lens with an adapter permanently fixed to it.  

My Super-Angulon M 4.0-21mm is constructed in the same way:
There is an M39 thread under the M bayonet.
Only a tiny screw needs to be loosened to remove the M bayonet and screw in the lens as an LTM lens.
Of course, the distance measurement also works.

[spydrxx]

Read the responses very carefully. Several folks are talking about LTM lenses which were "converted" to M mount lenses via adapters.

[frame-it]

21 hours ago, rivi1969 said:

Good evening,

I have seen some interesting old rangefinder cameras with LTM mount, however I couldn't find any adapter to fit M-mount lenses on those old bodies, there are thousands to adapt LTM lenses to M-mount bodies but not the other way around, so maybe there isn’t even possible?

Thank you!

Ricardo

look for older M lenses, that are actually LTM lenses but came with an LTM>M adapter screwed on

 

[rivi1969]

I was interested in a couple of LTM bodies and I thought that would be cool to use my current M-lenses on one of those film bodies, but now I see that is not possible, so I won't go that route. Thank you!

[a.noctilux]

I'm happy user of the two Leica systems LTM and M.

- most equivalent LTM when converted to M mount had gained more size and weight

like this Summaron 3.5/3.5cm

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M mount ...

- when possible I choose the LTM to use with LTM Leica and added 1.0mm adapters M to LTM lens

 - my best buys would be Super-Angulon 4/21, 35mm Summicron 'I' and Summaron 2.8/35 that have from factory the adapters

[Infantasy]

As my post #5 here, I had hesitation on using LTM lens but someone told me no need to hesitate so I got my first LTM lens of Summaron 35 f/3.5. As expected, I bought 2 LTM to M adapters but no luck. Both cannot match the thread of the lens causing the RF mechanism not work when focusing below 2m. I bought a third one and this time can link to the RF but the focus between RF and live view do not match. Now I am thinking to sell the lens out. Very bad experience on using LTM lens.

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[pippy]

46 minutes ago, Infantasy said:

As my post #5 here, I had hesitation on using LTM lens but someone told me no need to hesitate so I got my first LTM lens of Summaron 35 f/3.5. As expected, I bought 2 LTM to M adapters but no luck. Both cannot match the thread of the lens causing the RF mechanism not work when focusing below 2m. I bought a third one and this time can link to the RF but the focus between RF and live view do not match. Now I am thinking to sell the lens out. Very bad experience on using LTM lens...

That's very odd to put it mildly! Something must be badly out of alignment / adjustment. It's possible that the lens has been reassembled incorrectly at some point in its past.

As has been mentioned many times previously these adapters have been used by photographers - shooting with LTM on M cameras - for over 65 years so the concept is clearly very sound which suggests that, somehow, there is something very wrong with your set-up.

Can you be more specific about how, exactly, the adapters "cannot match the thread of the lens"? I've just double-checked with some of my own lenses/adapters and there is only one possible place for the lens and adapter threads to mate-up correctly so it's hardly a complicated undertaking. As you have a Leitz lens and a Leitz adapter there should be absolutely nothing to go wrong - yet in your case it seems something is amiss.

We really need to know more about the problem you are facing. Perhaps, as mentioned above, the Summaron has been dismantled and incorrectly reassembled by an inexperienced owner/repairman. Do you have any way of verifying that the Summaron is functioning properly in the first place? Do you have access to a screw-mount camera body? We have heard many tales about old lenses having been put together wrongly after repair as, unlike the rear thread/adapter process, the internal helicoids of some LTM lenses can be put together in the wrong orientation.

Please let us know more information and we'll try to help you get to the bottom of the matter.

Philip.

Edited October 16, 2021 by pippy

[spydrxx]

I too would be very interested in your specifics, as I've used LTM lenses with adapters quite successfully for over 6 years on both film and digital bodies. The only issue I ever encountered was that one wasn't the exact thickness and brought up the wrong framelines...a little polishing took care of that issue. Thousands of people have been using adapters with LTM lenses, so you really do need some assistance in figuring out your problem.

[Infantasy]

There is inherent huge error on the LTM adapter no matter produced from China or the original but the RF only allow tiny tolerance.  The first two adapters blocked the RF arm moves to the bottom as shown in my previous picture thus I bought the third one. This time the RF arm ables to move according to the lens helicoid but the resultant pictures are out of focus when the optical VF is in focused. I use the live view to check against the optical VF and confirmed they are not match. The actual focusing point as shown in live view is  about ten inches to a feet behind the optical focusing/overlapped point.

I am not sure whether it was reassembled by repairman as it was bought from used market but the retaining rings have some wear. Although there is no assembling info in the internet, may be I would dissemble and reassemble it again if no one want to buy this lens.

I will rather buy M-lens as the "investment" on LTM lens seems very risky.

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Hallo,

Look here: Leica M

[a.noctilux]

LTM lenses are great when they are in good shape.

So light and small ...with right adapter to M mount