M39 adapter

[Mauro]

I own some SLR M42 bodies and several M39 lenses: is it possible to install the M39 lenses on the M42 bodies, using an adapter? if so, what I should search for? and is it worth doing it?
Any tip and advice is really appreciated.

 

[venchka]

I'm no expert, but this is what I know from my own equipment:
The SLR M42 body film to lens flange distance is greater than the M39 lenses. If there were an adapter for the M39 lenses, you could not focus at infinity. Someone else will probably explain it better.

Wayne

 

[Trius]

I'm no expert, but this is what I know from my own equipment: The SLR M42 body film to lens flange distance is greater than the M39 lenses. If there were an adapter for the M39 lenses, you could not focus at infinity. Someone else will probably explain it better. Wayne

Right. The same is true for an M42 lens on my OMs. The only way to achieve infinity focus is to use an adapter with an optical elements that "corrects" this. These adapters would be more expensive if they are high quality.

And Wayne - Hello!

Earl

 

[Dwig]

There are two quite different 39mm thread mounts.

One in an old/antique "M39" mount used by some German (Praktika?) 35mm SLRs in the early '50s. It has the same flange to film (aka register) distance as the more modern M42 Praktika/Pentax SLR mount. There are adapters made and they can be made so that infinity focus is maintained.

The other is the LTM (Leica Thread Mount). This uses a slightly different thread and has a much shorter register distance (28.8mm) than M42 (45.46mm). LTM lenses can be adaptered to M42, but only for extreme closeup and macro use. The adapter plus the difference in register distances is the equivalent of adding a roughly 20mm extension tube. A 50mm LTM lens adapted to M42 will yield 1/2 life size closeup when the lens is set to infinity.