The M42 mount (also often referred to as Pentax mount in the U.S.A.) is one of the most widely used type of mounts. The M42 type scewmount was introduced in former East Germany by Contax and later further popularized by Pentacon, Praktica and Pentax (therefore it is known as a “Pentax mount” in the USA). Today a wide choice of M42 lenses exist from Carl Zeiss, Meyer-Optik Görlitz, Pentax-Takumar, Pentacon and others.

“electric” lenses have three yellowish electric connectors. Using an “electric” or a non-electric lens on a modern DSLR does not make any difference in terms of performance and usability.

M42 adapter for Micro 4/3, Nikon F, Canon EOS, Pentax-K, Sony NEX E-Mount, Sony Alpha and Fuji-X cameras

There are a lot of adaptors available – below you find a link to each camera brand:

M42 / Pentax mount to Micro-4/3 adapter

Connectivity to micro-four-thirds (mft) is unproblematic. The adapter is always quiet large which will increase the “size” of your lens. Focusing to infinity works fine. The only major drawback is that the images are cropped compared a full frame SLR. Even a 35 or 50 prime lens will feel like a telephoto. You can find the adapters here:

M42 / Pentax mount to Canon EOS adapter

You can find a compatibility chart of most vintage lenses on Canon EOS cameras here. Mounting an M42 lens to Canon EOS is normally unproblematic. It will allow you to focus to infinity and adaptors are quiet cheap at around 10 bucks. I would recommend that you get an AF confirm adapter:

M42 / Pentax mount to Nikon F adapter

Well my Nikon friends, this is not going to be easy. The good news is that there are two types of adapters available. The bad news is that mounting an M42 lens on a Nikon F camera will never work perfectly. As the size of the Nikon F mount is smaller than that of the M42 mount, even with an adaptor the lens cannot be perfectly positioned vis-a-vis the sensor. You therefore loose the possibility to focus to infinity with a normal adapter. Therefore some adapters are equiped with a corrective glass element. With these adaptors you can focus to infinity but the introduction of an additional glass element will affect the image quality. You can find M42 to Nikon F adapters here:

M42 / Pentax mount to Sony Alpha adapter

As with Canon EOS cameras, connecting a M42 lens to a Sony Alpha camera is pretty unproblematic. Focusing to infinity is possible. You can find the appropriate adapters here:

M42 / Pentax mount to Sony NEX E-Mount adapter

As with Canon EOS cameras, connecting a M42 lens to a Sony NEX camera is pretty unproblematic. Focusing to infinity is possible. You can find the appropriate adapters here:

M42 / Pentax mount to Pentax-K adapter

Connecting a M42 lens to a Pentax-K camera is unproblematic. Focusing to infinity is possible. You can find the appropriate adapters here:

M42 / Pentax mount to Fuji X adapter

Connecting a M42 lens to a Fuji-X mount camera is unproblematic. Focusing to infinity is possible. You can find the appropriate adapters here: