As long as third-party manufacturers make adapter rings, you can use nearly any lens on any camera. There are adapters that even allow the use of medium format lenses on 35mm cameras. Even though there are adjustments to be made in your shooting habits, you can use the Nikon manual lenses on a Pentax camera.
Instructions
1. Purchase a Nikon lens to Pentax camera adapter. There are available, both new and used. The adapter is a ring that has the Nikon lens mount on one side and the Pentax lens mount on the other.
2. Attach the Nikon lens to the adapter ring as you would to a camera body. It will snap in on the bayonet mount just as it would on a camera.
3. Attach the Nikon lens-and-adapter combination on the Pentax camera as you would a regular Pentax lens. For example, if you have the quite bright Nikon 50mm f/1.2 "normal" lens, it will work in the normal range just as well as a Pentax lens with better glass. This manual lens has a wider F-stop than most 50mm lenses, so use it in low-light situations you might not be able to use another, standard lens.
4. Use the manual focus on the lens to focus and the manual aperture ring to set exposure. If the Pentax camera has a built in light meter, it will work through the Nikon lens. It will tell you the settings for the aperture and shutter speed.
5. Shoot at least one test roll of film or one memory card of photos through the Nikon-Pentax combination system to make certain your exposures are correct before shooting any serious assignments. Another lens to use is the Nikon 35-70mm f/3.5 AI-s manual focus lens. It is a wide-angle to portrait zoom with good clarity. It has a short zoom that is a good test lens because it lets you use varying focal lengths, all at the same maximum aperture.
Tags: Nikon lens, Pentax camera, Pentax lens, adapter ring, Attach Nikon
