Adapting Nikon F Mount lenses.
Almost all Nikon F-mount lenses (Pre-AI, AI(*see below), AF-D, AF-S, G) can be mounted except for Pronea IX APS lenses.
A mount shim ring is required during the mounting of F mount lenses. See FIG. 3.
1. Take out one piece of the black mount shim (see Note 1 below) from the
2. Detach the outer shim ring from its centre unused material.
3. Place the shim ring firmly and flat onto the lens rear mounting surface.
4. Align the mounting mark on the lens with the red circle mark on the mount ring, same as Pentax K mount.
5. Turn the lens clockwise to mount.
6. While depressing the lens release button, turn the lens anti-clockwise to separate from camera.
1. The purpose of the mounting shim to secure the mounting of Nikon F mount lenses. It does not compensate for the difference in F-K mount register distances.
As such, the distance scale (where present) on Nikon F mount lenses will not be accurate/applicable as infinity focus will be achieved earlier at around the 5 metres mark.
2. Some Nikon lenses have a dust gasket (black rubber ring) at lens mount and will cause mounting on PK+MM to be difficult. There is no need to use the mounting shim for these lenses. It is also not recommended to use these lenses unless necessary.
* Information on mounting AI/AIs lenses.* (updated on 1st May 2014)
It is noted that some Nikon AI/AIS mount lenses cannot be mounted on the PK+MM. It is due to the protruding tab on the lens aperture ring that is preventing the mounting.
To overcome this, the only solution is to file or sand down the inner side of the smaller tab by 1mm to allow mounting (green area shown in picture below). This does not affect the use of this lens on its original mount.
0.9mm thickness nylon washers for Nikon F mount lenses