Sleeping with the enemy.

Perhaps John should look away, now!...






Nikkor pre-AI lenses can go on Pentax K mount cameras, without an adapter. Not properly, but well enough... And work!

Those who do want to know the results are not looking away now.....

Coker.

Strange that no one else has mentioned that

Being the reckless and irresposible little bleeder that I am, I had the idea of seeing if the lenses from my Nikkormats would go on a Pentax. I didn't think they would, but it was a slow day and I was a bit bored.

The Nikon bayonet fits completely within the K mount throat. I have found that it is possible to partially mount a Nikon lens. It must go on upside down, though, and will not turn fully to lock in place, like a Pentax lens. The two lenses in the picture above, will turn a few degrees and stay firmly in place. I did not force them any tighter for fear of causing damage.
Exposure is manual only, of course. With the istD set on Manual, the green button is pressed to get a meter reading, and shutter released.
Images came out well.

I've obviously stunned you all into outraged silence.

OK - one question - is this worth doing? And if so, why?

Actually, that was two questions. But it's late and I've had a few beers...

It's worth doing for me, Tony. That Nikkor 105mm f2.5 is one of the nicest lenses I own. I'm now looking forward to using it digitally.

Actually, those old pre-Auto indexing Nikkors are more useable on a Pentax Dslr, than they are on a modern Nikon. They fit properly on all Nikon digital SLR's, but the camera won't meter through them. On a Pentax, they don't click fully home (obviously), but they go on well enough to stay put and the camera will meter with them on, in stop down mode. (green button).
Nikon lenses are some of the finest ever made, and if they can be used, even with a bit of inconvenience, like having to be upside down, and in manual only, then why not?.
Adapters do exist that allow Nikon lenses to be used on Pentax cameras, but they incorporate a glass element of doubtful quality, to allow infinity focus. As this element will certainly degrade the image quality, it rather defeats the point of using a fine Nikkor on a Pentax.

I see a new challenge ahead! Thankyou and merry christmas!!

Cool!!

The green button is great btw. It simply meters whatever is thrown at it. I tried it with a preset (dual ring) aperture lens last night, which had no aperture-camera coupling whatsoever and it worked great ( bit inaccurate at small apertures though, i.e < f16

mowog, what is auto indexing in Nikkor lenses and why can't those lens be used on pentax bodies too? TIA

A DISCLAIMER:

I would not encourage anyone to start trying to wedge old Nikkors on to their nice new and expensive K5, or anything. My camera is old, and I was willing to take the risk of killing it, by trying this out.


Smeggy.

Before 1977, Nikon cameras had to be told what lens was being mounted to it, by engageing a little prong on the lens, with the meter pin on the camera body. After mounting the lens, the aperture ring had to be turned all the way to maximum aperture, then back again, to 'Index' the meter (tell it the maximum and minimum apertures). In 1977, Nikon introduced 'Auto indexing' or AI cameras and lenses. These had an extra ridge on them that told the camera what the aperture range of the lens was. Pre AI lenses could still be used in the old way on the new cameras, and old non AI lenses could be modified by Nikon service agents.
I don't know if later AI lenses will also go on a Pentax. I only have pre AI nikkor lenses. I suspect not, as the AI ridge may get in the way.

Ahhh cool. - thanks for the info

Long time know fact (at least to some of us...).
The physical similarities of early Nikon (F?) mount and K mount were too great for some and they tried.
As a result, yes you can use pre AI Nikkors on K mount bodies, they will not lock on the body bus should fit tight enough not to fall off. And they will be upside down, but that will only matter to those standing in front of the camera anyway...

2 questions though:
how is infinity focus?
how does one recognize pre AI lens... I used to think the lenses with the "lips" are pre AI but I'm not sure now...

thanks...

Ahhh...back home now and the beer's wearing off. I do, however, have a *istDS which I might try. Having said that, a quick look at the back of AP seems to suggest these buggers aren't excatly cheap!

Tony.

Your istDS does not have a green button. I don't know if the camera will meter through the Nikkors on Av. I only tried on M and pressing the green button.

Axl.

Bugger!.. And there was I smugly thinking I had discovered something nobody else had even thought of trying!

Yes, the Nikkors do focus to infinity on a K body.

As for identification. I'm not exactly sure, never having had an AI lens, but I suppose that all pre AI lenses had a little fork type prongy thing on them (you can see it on the 105mm lens, in the picture above).
AI lenses have some sort of ridge on the lens flange, that connects with something on the camera body, but also have a forky prongy thing, to make them usable on earlier bodies, like my Nikkormats. The latest nikkors do away with the prongy fork, altogether. So.. If the lens has a forkyprong type thingy, but nothing on the flange, it's likely to be pre AI. Also the older type have nice chunky scalloped metal focus rings and Nippon Kogaku written on the front.