LTM to M mount...how does it work?

[rpavich]

I'm new to the rangefinder world, I have an Epson R-D1s that I love and I just realized that I have a jupiter 50mm lens that's just sitting in a drawer.

It's got an LTM mount and I'd like to get an M adapter to give it a whirl but I was wondering: if a lens isn't "coupled" then how does it achieve focus with a rangefinder?

 

[kbg32]

There is no "coupling" between lens and camera in a rangefinder except for the rangefinder focusing cam on the back of the lens, whether LTM or M mount. Well, there is for digital Ms, but this is all you need to know right now. Get the proper LTM to M adapter and enjoy your Jupiter without any problems.

 

[B-9]

The lens should be coupled if its a Jupiter-8

The coupling action happens inside the adapter the same way it works on a screwmount body.

A cam pushes against a roller, roller transfers this movement to the Rangefinder.

For the Epson, Any old LTM-M adaptor will work as you manually select the framelines you want on top of the camera.

I think your overthinkng the problem, ive got a cheapo adapter if you want to PM me.

 

[rhl-oregon]

What Keith said. Except even an improper i.e. cheap ltm->M adapter will probably do the trick on a digital. I have a cheapo--engraved "50-57mm" instead of 50-75--but it works fine on my XE1 and A7 as well as on my M5. All other things being equal, still, a more expensive adapter is the better choice, and will let your Jupiter be a nice 75mm Sonnar on the RD.

 

[Dwig]

I'm new to the rangefinder world, I have an Epson R-D1s that I love and I just realized that I have a jupiter 50mm lens that's just sitting in a drawer.

It's got an LTM mount and I'd like to get an M adapter to give it a whirl but I was wondering: if a lens isn't "coupled" then how does it achieve focus with a rangefinder?

Leica designed the "new" (read: early '50s) M mount with the ability to adapt LTM lenses in mind. As a result, the adapters work very well.

There are two coupling issues:
1. focus: Both LTM and M mount use identical focusing coupling so if the adapter is properly made (exactly 1mm thick) focusing will couple accurately. The only time problems arise is when cheap poorly made adapters that are inaccurately machined are used.
2. Auto frameline switching on Leica M bodies: The M flange varies from lens to lens or adapter to adapter to set the appropriate frameline. If you use the adapter on a Leica M-series body then you want to choose an adapter that sets the correct frameline for the lens in use. If you use a body that doesn't have this auto frameline function or are using a lens for which your body doesn't provide a frameline (e.g. 21mm, ...) then any variant of the LTM>M adapters works.

 

[kermaier]

What Keith said. Except even an improper i.e. cheap ltm->M adapter will probably do the trick on a digital. I have a cheapo--engraved "50-57mm" instead of 50-75--but it works fine on my XE1 and A7 as well as on my M5. All other things being equal, still, a more expensive adapter is the better choice, and will let your Jupiter be a nice 75mm Sonnar on the RD.

Incorrect: Any adapter may work on mirrorless or other live-view digital cameras like your XE1 or A7, but only an adapter with precisely machined thickness will provide good results on a camera with mechanical focusing linkage, like the R-D1 or M8/9. (And even on your mirrorless bodies, if the adapter has uneven thickness, you may be able to focus fine, but you may see focus shift or perspective distortions across the frame.)

I recommend using only vintage Leitz adapters in good condition, or Cosina Voigtlander adapters, which are of very high quality. (CameraQuest is now selling adapters from Rayqual, since the CV adapters are discontinued, but I have no experience of those yet.)

Regards,
Ari

 

[kermaier]

Order one of these:
https://www.keh.com/231238/leica-m-adapt-50-sm-to-m

 

[rpavich]

Thanks everyone..any recommendations on a good adapter brand?

 

[Huss]

Thanks everyone..any recommendations on a good adapter brand?

Shop ebay for a used real Leica one, or a real Cosina Voigtlander one (most probably used).
Cameraquest sells new Rayqual ones which are meant to be good.

I just went through this process, and all the cheap ones I tried did not line the lens up properly i.e. the focus mark which is meant to be at 12 o'clock on the camera body was off by a lot, as well as having issues with the correct frame lines appearing.
I tried Fotodiox - did not line up, Metabones - did not line up AND gouged my lens mount!, Fedka - expensive (something like $75 after shipping) and did not line up correctly. He also refused to post my polite but accurate review, he only shows reviews which praise his products..

It's only when I used the CV and Leica ones that I got a decent result.

 

[Huss]

FYI, you can also place an ad on this site asking if anyone has a 'real' one they are willing to sell. I did that and received multiple offers (and bought). For a CV Voigtlander one $40 seems the happy spot.

 

[ascherjim]

For my Epson RD-1 camera (I have no Leicas, sob?) i have used the adapters from Fotodiox without problem, and they're much cheaper. Whether they're not accurate with Leicas (see above entries) I have no experience, but Fotodiox products (and advice) have satisfied me over many years with many of my cameras.

 

[rpavich]

For my Epson RD-1 camera (I have no Leicas, sob?) i have used the adapters from Fotodiox without problem, and they're much cheaper. Whether they're not accurate with Leicas (see above entries) I have no experience, but Fotodiox products (and advice) have satisfied me over many years with many of my cameras.

Well..I bought a Fotodiox adapter just to see how i like it. I couldn't see spending $75.00 to adapt a $12.00 lens. Later on if I have a quality LTM lens that I need to adapt and the Fotodiox isn't cutting it, I know where to go now.


thanks for the help.

 

[David Hughes]

Hi,

There have been so many comments about the copies of the Leica adapter on this forum that - sooner or later - the Chinese will realise and start to get the frame-line changer right. I think the problem is that a machinist (or two) has just copied them and not realised quite how they work. You need a Leica M and a selection of lenses to discover this...

BTW, genuine Leica made lenses and genuine Leica camera bodies can drift out of alignment and then the focussing mark will be at 1 or 2 o'clock. It's easily adjusted but can be ignored.

BTW 2, not all lenses with the 39mm thread are suitable for coupled range-finder bodies. Some SLR's used them and the registration was different too.

BTW 3, I've bought cheap ones and been pleased that they worked and dear ones and cursed the seller or whoever bodged them. Judgements based on prices often fail.

Regards, David

 

[rpavich]

Well, I guess there was no need to worry, I got the adapter, put on the Jupiter-8 and it works fine...spot on.

I don't know how, but it does 🙂