Originally posted by THoog My math OCD is acting up: 1.04mm. That's more of a shim plate than an adapter.
I think you slightly misinterpreted my point. It isn't possible to make an N to PK adapter that is only 1.4mm thick. You could not simply put a shim between the camera and the lens because then the lens could not be forced to grip on the Pentax body bayonet. Seems to me there are four choices for mounting a Nikon lens to a Pentax body:
1) Force the lens onto the PK body bayonet in which case if there is a hard stop for infinity on the Nikon lens (eg it is a near normal or WA lens), that infinity stop will be incorrect - you have to focus the lens slightly closer to get infinity.
2) Use a Nikon to Pentax adapter that has a lens in it = basically a simple 1.4X teleconverter. You have infinity focus, but you pretty much defeat the purpose of mounting normal or WA lenses, and IQ will probably suffer more than you'll be willing to accept;
3) Use a glassless Nikon to Pentax adapter, which loses infinity focus but retains the lens' IQ. With normal or WA lenses this would only be good for macro, but with longer telephoto lenses it is a viable method, the longer the lens the more satisfactory it will be.
4) Install a PK + MM multi mount, provided you have a Pentax body that will accept it and you are willing to deal with the various caveats. This method might be attractive if you have a second Pentax body that will accept the replacement flange.
Regardless of the method used, there will be no lens-camera communication, therefore: no AF, no EXIF, and manual diaphragm operation only.