Nikon released their original F camera in 1959. Reliable and rugged with a large assortment of high quality lenses, it became a photojournalist's standard piece of equipment. The F was the world's first truely successful professional 35mm SLR and continued in production through 1974.
Ever aggressive at the time, Nikon paid keen attention to user and repairshop feedback regarding their F camera and the result was the F2. The F2 is a rock. More solid than an F, a little bigger, a swing-open back for easier loading and a more reliable optional motordrive capable of 5 frames per second AND power rewind. The F2 quickly took hold in professional markets.
There were several F2 models over the years, mostly differing in the specifications of the removeable metered viewfinder. The F2AS was the last and best with advanced metering (as low as EV -2), a built-in meter illuminator and LED exposure readout. The "A" stands for "AI" which means it is compatible with any Nikon F-Mount AI or AIS (or AF) lens.