Douglas Greenberg , Feb 15, 2005; 04:34 p.m.
There is a problem with regard to using M42 lenses on a Nikon mount, even with a mount adapter, inasmuch as you cannot reach infinity focus. The answer has been to devise adapters that include a "supplementary lens," usually one that is very cheap. The result is a degradation of image quality that renders the whole experiment kind of dicey.
Some of these adapters supposedly work without such an additional lens, but I would guess that you would sacrifice distant/infinity focus in order to use them.