[justtakingpics]

I found this product:

Fotodiox

I didn't know you could use anything but pentax and screwmount lenses on Pentax. Do any of you use other manual lenses? Do they work okay being on the Pentax dslr body?

[eddie1960]

the problem with using these is there is another lens element being added to let it focus to infinity and it degrades lens iq. not worth it unless you already own a chunk of old canon FD glass and want to get some use from it (I would tend to then remove the glass and use it without infinity focus then)

Nikon lenses will mount in many cases without the adapter but they won't lock in place or focus to infinity. that being said there are a couple of people using them here

edit

this thread will cover off the nikon lens on pentax thing

https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/37549-nikon-lens-pentax.html

[Lowell Goudge]

I have a similar thing, actually 2 of them, one Nikon to PK and one canon to PK

They do allow focus to infinity, but the nikon one has a measured multiplier of 1.25 and the canon one a multiplier of 1.45.

they also tend to belad colors at edges when used on the respective 50mmF1.8 lenses I tested them with,

I got them just so I could use a nikon or canon lens without butchering it.

Lenses work like M42 lenses, in stopped down metering mode only.

My conclusion was that due to the multiplier they were only good for telephoto and normal lenses.

[boriscleto]

Non AI Nikon lenses can be force fit to K-mount without modification. AI Nikon lenses need to be modified a bit to fit without an adapter. Canon FD lenses need a corrected adapter to work at all. Without the corrective glass the adapter is useless for anything other than Macro lenses. The focusing distance is about 3 inches at infinity.