I have some lenses off my old Pentax MZ50 SLR camera, and I would like to buy a new camera body. How do I find a compatible camera?

  • 2
    \$\begingroup\$ Possible duplicate of Can I use lens brand X on interchangeable lens camera brand Y? \$\endgroup\$
    – Philip Kendall
    Aug 29, 2019 at 8:06
  • \$\begingroup\$ Usually adapter questions in which a camera has already been chosen are marked as duplicates of the Lens-X/Camera-Y question. While information contained at that question is relevant, no camera has yet been decided upon in this one. So I'm not sure it should be closed as a duplicate (though perhaps unclear or too broad because the specific lenses are not identified and there are a lot of K-mount variants to consider). \$\endgroup\$
    – xiota
    Aug 29, 2019 at 11:11
  • \$\begingroup\$ There are a lot of K-mount variants. Can you specify exactly which lenses you have? Do they have autofocus? \$\endgroup\$
    – xiota
    Aug 29, 2019 at 11:13
  • 1
    \$\begingroup\$ New as in actually new, or anything that is digital? \$\endgroup\$ Aug 30, 2019 at 8:07

3 Answers 3


According to Camera Wiki, the Pentax MZ-50/ZX-50 uses KAF2 mount lenses. It likely also works with older (manual focus) K-mount lenses, though beware the Ricoh variant, which has a pin that can get stuck on the screw drive of some Pentax bodies.

There are significant trade-offs in functionality when using old lenses with digital cameras. With old Pentax-branded lenses, it can be worthwhile. However, you have a third-party lens that would likely lose autofocus when adapted. Unless you specifically enjoy using adapted lenses, this is likely not the best way for you to move into digital.

To use your old lenses, your options include:

  • Using a mirrorless camera with adapter. However, you would lose autofocus and electronic aperture. See Can I use lens brand X on interchangeable lens camera brand Y?

  • Use a Pentax camera that uses a modern variant of the K mount. There are full-frame DSLR (K-1), APS-C DSLR (K-3 and others), and APS-C mirrorless (K-01) cameras. New models are released regularly, so check to make sure you are looking at the latest ones.

    • The lenses you have likely require a screwdrive to operate autofocus. Check the specific camera models you're interested in if autofocus matters to you. The following image shows what to look for:

      Pentax Mount

    • According to Mark Roberts: Pentax Lens/Camera Compatibility, there are some other issues you should be aware of (emphasis added):

      Some third-party lenses (Vivitar and others) from the manual focus era have an issue that causes problems with later Pentax cameras: A flange which is meant to protect the diaphragm actuation lever but which is much bigger than is really necessary. If your particular lens has this "feature" it will prevent the lens from being mounted on many Pentax cameras, including all the digital SLR's.

      Older versions of the Sigma 24-70 f/3.5-5.6 autofocus lens are incompatible with Pentax Digital SLR's — They won't autofocus or stop down the lens for shooting and have several other issues. Newer versions of this lens are labeled "ASP HF" and should be OK.

See also:

  • \$\begingroup\$ Correction: every Pentax autofocus body, either film or digital (as of August 2019, at least!) has autofocus screw-drive motor built-in, every DSLR after K100D Super has additional contacts for SDM/HSM/PowerZoom functionality, so any Pentax DSLR in the last 12 years will work just fine. \$\endgroup\$
    – elkarrde
    Aug 30, 2019 at 6:28
  • \$\begingroup\$ @elkarrde Thanks. Revised. \$\endgroup\$
    – xiota
    Aug 30, 2019 at 6:38
  • \$\begingroup\$ Wonder how a lens could not "autofocus or stop down" on that lens mount (which has mechanical stop down and autofocus linkages) unless it isn't even recognized as an electronic lens at all :) \$\endgroup\$ Aug 30, 2019 at 14:42
  • \$\begingroup\$ @rackandboneman – I don't know. I'd guess some type of electronic communication issue. With Minolta AF, even though the electronics aren't really used for anything other than lens identification, the camera will refuse to operate the lens, even though it's in perfect mechanical condition if it can't connect to the lens. There could be similar issues with other mounts. \$\endgroup\$
    – xiota
    Aug 31, 2019 at 0:27

Pentax MZ50 uses so-called "crippled" Pentax KAF2 mount, meaning you could use its lens with any Pentax DSLR ever built.

Technically, judging by the camera that lens was being used on, you could probably use whatever Pentax K-mount camera you can find, either digital or analogue, from Russian Zenit 122K, legendary Pentax K1000 and MX, many Ricoh and Chinon models, to modern digital SLRs, mirrorless K-01, and full-frame K-1. If the camera supports aperture automation, it will work, if the camera supports the KAF2 autofocus protocol, it will work. If it works on MZ50, it will work on any film autofocus body, it will work on any DSLR as well. If the lens has an aperture ring (and it probably does), it will work on all other manual focus cameras with manual focus only.

On the other hand, you can always adapt the lens to other systems, but adapting K-mount lenses means any communication between the camera and the lens is lost, there's no autofocus, there's no aperture control from the camera. Any mirrorless camera will work, Canon APS-C bodies work just fine, avoid Canon full-frame bodies, the mirror will hit lens aperture levers. Nikon and Sony/Minolta DSLRs aren't compatible. Olympus and Panasonic DSLRs are good to go. As long as the lens has an aperture ring, it can be used in manual mode.

TL;DR: you can use that lens on almost any K-mount camera, film or digital, Pentax or some other brand, as long as it has K-mount.


Googling seems to indikate that your old camera is using pentax k mount. That mount is still used by pentax dslrs. A quick search found in the swedish market found a new pentax k-50 with a kit lens for 5000 SEK (aprox 500€).

With this camera the lens will physically fit. What is harder to know is if autofocus will work well. On Canon old sigms lenses are known for autofocus trouble but I do not know about the situation for pentax. (Is your lens autofocus electronic or screw drive)

Note also that this is an apsc camera so the field of view will be narrower than on the 35mm film camera.


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