The Nikon F-Mount was launched with the Nikon F camera in 1959 and has remained virtually unchanged since, making it the only lens mount still in production over 5 decades after its introduction. The camera mount comes essentially in 3 flavors: F, AI-S and AF, with some minor adaptations for particular cameras, mostly the digital entry-level models, which feature 2 extra screws and the minimum aperture confirmation notch, discussed later on.
Review of the ATX Pro 12-24 mm f/4G Tokina. Strengths and weaknesses, links to pro reviews. Conclusión: big bang for your buck.