Using pentax M42 lenses on leica M mount

I have had, for some time, a number of M42 pentax lenses. Can I use them on a leica M mount? Is there an adapter out there? Could you direct me? Thanks. I'd like to try them before trying to on-sell. Any advice greatfuly appreciated. Regards, Arthur (apiarist1).

I have had, for some time, a number of M42 pentax lenses. Can I use them on a leica M mount? Is there an adapter out there? Could you direct me? Thanks. I'd like to try them before trying to on-sell. Any advice greatfuly appreciated. Regards, Arthur (apiarist1).

M42 Pentax lenses will screw into a LTM-to-M adapter (and will mount to a Leica M camera), but they will not couple to the RF and the lens-to-film plane distance is wrong. Short answer: it won't work.

The one scenario where you could is, if you are talking about a digital M body that has a live view option and you use the back LCD in live view or an electronic finder plugged into the hot shoe to allow for manual focus since the rangefinder is never a focus option, so digital M’s with no live view option would not be useable this way.

Adapters surely exist. - Look at ebay If you are somewhat lucky you can zone focus your old treasures on them. If you are unlucky you might need to shim a cheap adapter slightly.* Clarifying: I can't proof if "adapters" are off. I bought a set of K+F to Fuji X ones and it seems to me that their LTM is shorter than the M & K ones but I am not sure if my old 85mm Jupiters are within which specs....

If you own a LV capable "M" body (""s because it might be a MILC adapted to take M lenses) $16 will get you going.

If you have only a pure RF (M8 etc.)

the rangefinder is never a focus option

but you might be able to evaluate your heritage glass by putting tripod and tethered laptop on your porch or balcony and doing focus by trial & error.

You can get an M42 to Leica M adapter. If you have a newer camera with live view, you can use that to focus. As somebody who has done a lot of shooting with adapters and mirrorless cameras, I’ll just say that the shooting experience is never as good as the combination of native lens and camera, but adapters are cheap and you might as well try it.

There are adapters which have RF coupling. Some require that you transfer the distance reading from the adapter to the lens. This one apparently does not, although I'm not an expert in how the Voigtlander Prominent works.

 

Link: Fotodiox Pro Lens Mount Adapter - Voigtländer Nokton & Ultron 50mm Lenses to Leica M Mount Rangefinder Camera Body with Leica 6-Bit M-Coding and RF Coupled Focusing

 

Link: Voigtländer Prominent I & II

Fotodiox Lens Mount Adapter with Leica 6-Bit M-Coding - M42 Type 2 (42mm x1 Screw Mount) Lens to Leica M Mount Rangefinder Camera Body

No RF coupling.

LTM-

For the record, LTM is "Leica Thread Mount" = 39mm (technically - 39 mm in diameter and has a thread of 26 turns-per-inch or threads-per-inch (tpi) (approximately 0.977 mm pitch) of Whitworth thread form)

 

M42 is nominally 42 mm in diameter and a thread pitch of 1. It will not connect to a LTM adapter directly

... M42 is nominally 42 mm in diameter and a thread pitch of 1. It will not connect to a LTM adapter directly

Thanks for clarifying.

Thanks for the link, billblackwellphotography (and others - yes, it will be used on a digital M, so live view). Ordered now. Regards, and thanks again, Arthur

I have not seen an adapter but I think it's not difficult to make one. However, without rangefinder focusing it would be a big drawback. Besides, why use anything less than the Leica lenses on a Leica?

OP states he is using live view so RF focusing isn't an issue.

I use one similar to this for my Pentax 50/1.4 Super-Takumar. The adapter is not RF coupled, but with Live-View this is not an issue.

 

Adjustable M42 Lens to Leica M Mount Camera Adapter M6 M8 M7 M9 US Seller | eBay

 

I made an RF cam to use the Pentax on my M8. It's very good, but the Konica 50/1.7 AR-Mount is even better. I ended up adapting the Canon 50/1.4 FL Mount lens, and also a Minolta 50/1.4 MC series lens to RF coupled Leica M Mount. All maintain coupling to 0.65m.

I have had, for some time, a number of M42 pentax lenses. Can I use them on a leica M mount? Is there an adapter out there? Could you direct me? Thanks. I'd like to try them before trying to on-sell. Any advice greatfuly appreciated. Regards, Arthur (apiarist1).

Leica adapter 22232. Very rare. Found one a few years ago but haven't tried it.

Leica adapter 22232. Very rare. Found one a few years ago but haven't tried it.

For the price people are asking for those, you could probably find a decent Summitar.

Many years ago I was looking for a 28mm lens for my Leica/Canon7 bodies but did not want to spend $$$$- So I bought a M42 28mm f/2.8 as cheap as M42 lenses are. Back then, there was a used equipment store in the (german) town where I work, and in one of his grab boxes we found a M42 to M39 adaptor with suitable length to compensate for the back focal length. With 28mm you can easily "guesstimate" focussing. This, however, will be difficult or practically impossible with longer focal length. You can use one of the (expensive) adaptors with a rangefinder coupling mount (you have to set the focus on the lens separately), or use an old rangefinder accessory.

I've never tried any of my M42 lenses on my Leica bodies, but I did try a 17mm Tamron on a Nikon Adaptall mount, using a Nikon->Leica M adapter, and zone focusing. It worked out quite well. As stated above, it is pretty easy to achieve good results with wide angle lenses, where it becomes a much larger issue is with shorter focal lengths as focusing becomes much more critical, and if one is using the lenses wide open, you lose the advantage of DOF to bail you out. Having said that, my first 35mm camera didn't have a rangefinder, so guesstimating distance information, AKA zone focusing, wasn't something new to me.