[Pentaxor]

Nope, I don't think so...
I tried a Nikon type lens (100/2.8) with the lens removed from the Pentax\Nikon adapter and I could only focus the subject at around 24" distance.

I see. so this makes it ideal for macro use only (MFD to 24") ? how about the IQ? is there any sign of IQ degradation or difference with or without the adapter corrective lens attached?

[troyz]

. . .

The other option depending on lens is a reversible conversion to k-mount by replacing the F with a K. There are several threads around on the various ways to use pre AIS lens on dSLR Pentax bodies.

FWIW, here's Sean Carpenter's dpreview thread on nikon-to-pentax mount conversions:


Using Nikon F Lenses On Pentax K Bodies (LBA Post): Pentax SLR Talk Forum: Digital Photography Review

[stevewig]

I see. so this makes it ideal for macro use only (MFD to 24") ? how about the IQ? is there any sign of IQ degradation or difference with or without the adapter corrective lens attached?

Macro use, with corrective lens removed, would certainly work.

Regarding the IQ degradation - yes of course there is some degradation, including PF-ing particularly at lowest and highest F stops. Intermediate F stops seem OK provided you don't pixel peep comparison.

Also note that many (if not all) Non-AI Nikon lenses will physically fit on the Pentax and, once installed, work without degradation and focus to infinity. I have one such lens myself that works great on my D80 and K10D.

[Pentaxor]

Also note that many (if not all) Non-AI Nikon lenses will physically fit on the Pentax and, once installed, work without degradation and focus to infinity. I have one such lens myself that works great on my D80 and K10D.

do you mean without the adapter? how were you able to fit it in? what particular Non-AI lens?

[stevewig]

do you mean without the adapter? how were you able to fit it in? what particular Non-AI lens?

Check out this link:

https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/66701-modify-m...-use-k10d.html

The NON AI nikon lens does not have the aperture ring and other such physical obstacles that physically prevent mating a modern nikon lens onto a pentax. This is why you need the adapter for all modern nikon lenses. Although it is not a perfect fit, and by using normal common sense and care, the lens will fit and rotate enough so that you can actually use it.

I believe, without researching it, that the registry distances for the nikon and pentax are within 1mm. In any case, once you have been able to physically install the nikon lens (as you can with most - if not all - of the older "Non AI" lenses) then they will work without any negative IQ effects.

Remember that you will always have only manual focus capability with this setup, but you will have the normal metering as with a M pentax lens.