3rd party lenses

Mike Dowling · 08-25-2017, 02:34 AM

I have a K50. These are probably very naïve questions for long term Pentax users but here we go anyway.

Is it possible to use Nikon, Canon, Adaptall mount lenses on the pentax k ?

If so, are functions like auto focus still useable?

**boriscleto** · 08-25-2017, 03:10 AM

Adaptall is a manual focus mount, it will work with a K-mount adapter.

There are no auto focus adapters for Nikon or Canon mounts. Manual focus adapters for Nikon F-mount are basically a short tele-converter. Leitax makes a mount replacement that can convert some manual focus F mount lenses to K mount. The old Canon FD mount can be adapted with a similar short tele-converter. There are no Canon EOS adapters for K-mount.

dConvert · 08-29-2017, 07:57 AM

Originally posted by boriscleto

Adaptall is a manual focus mount, it will work with a K-mount adapter.

There are no auto focus adapters for Nikon or Canon mounts. Manual focus adapters for Nikon F-mount are basically a short tele-converter. Leitax makes a mount replacement that can convert some manual focus F mount lenses to K mount. The old Canon FD mount can be adapted with a similar short tele-converter. There are no Canon EOS adapters for K-mount.

Nikon lenses have a slightly longer rear focal distance than PK mount. I've heard it is possible to get them to (miss)mount on a PK mount by turning them part way round. With the registration being slightly shorter than they are designed for the lens will then focus beyond infinity, loosing some of the close focus capability of the lens... Of course AF & electronic aperture will not be available with this.
I've not tried, but if miss mounting works the Nikon lenses could be used with a Pentax 1.7x AF teleconverter to give limited AF

There are two types of Adaptall2 K mounts, the PK version & the PKA version. Both work but the PKA is better giving camera control of aperture.
M42, T2, C/Y & medium format lenses can also be adapted readily to Pentax bodies in fully manual mode.
It is possible to jury rig adapters for many other lenses if infinity focus & auto features are not required.

08-25-2017, 02:34 AM	#1
Mike Dowling New Member Join Date: Jul 2017 Posts: 11	3rd party lenses I have a K50. These are probably very naïve questions for long term Pentax users but here we go anyway. Is it possible to use Nikon, Canon, Adaptall mount lenses on the pentax k ? If so, are functions like auto focus still useable?

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08-25-2017, 03:10 AM	#2
boriscleto Loyal Site Supporter Join Date: Dec 2009 Location: North Syracuse, NY Photos: Gallery Posts: 16,475	Adaptall is a manual focus mount, it will work with a K-mount adapter. There are no auto focus adapters for Nikon or Canon mounts. Manual focus adapters for Nikon F-mount are basically a short tele-converter. Leitax makes a mount replacement that can convert some manual focus F mount lenses to K mount. The old Canon FD mount can be adapted with a similar short tele-converter. There are no Canon EOS adapters for K-mount.

08-29-2017, 07:57 AM	#3
dConvert Junior Member Join Date: Mar 2010 Location: Essex Photos: Gallery Posts: 41	Originally posted by boriscleto Adaptall is a manual focus mount, it will work with a K-mount adapter. There are no auto focus adapters for Nikon or Canon mounts. Manual focus adapters for Nikon F-mount are basically a short tele-converter. Leitax makes a mount replacement that can convert some manual focus F mount lenses to K mount. The old Canon FD mount can be adapted with a similar short tele-converter. There are no Canon EOS adapters for K-mount. Nikon lenses have a slightly longer rear focal distance than PK mount. I've heard it is possible to get them to (miss)mount on a PK mount by turning them part way round. With the registration being slightly shorter than they are designed for the lens will then focus beyond infinity, loosing some of the close focus capability of the lens... Of course AF & electronic aperture will not be available with this. I've not tried, but if miss mounting works the Nikon lenses could be used with a Pentax 1.7x AF teleconverter to give limited AF There are two types of Adaptall2 K mounts, the PK version & the PKA version. Both work but the PKA is better giving camera control of aperture. M42, T2, C/Y & medium format lenses can also be adapted readily to Pentax bodies in fully manual mode. It is possible to jury rig adapters for many other lenses if infinity focus & auto features are not required.