F-Mount

=Pinout=

Some observation of patents/manuals and investigation different lens types result in following information: Each type of lens connector support all pins from previous version and introduce new extension pins for a new functionality. The evolution of F-mount connector: AF -> AF-S 8-pin -> AF-S 10-pin. Old AF lens can still have autofocus using mechanical coupling that is available in some high-end cams like D7000.

The most interesting rumor is that Nikon Pro Bodys have better Autofocus. There are several facts that approve this:
 * Nikon Pro Bodys use batteries with higher voltage. For example, D3 uses EN-EL4a rated 11.1V or D4 EN-EL18 rated 10.8V, against D5100 with EN-EL14 rated 7.4V. It seems this higher battery voltage is not made available to lenses. Additionally, testing many lenses at different voltages (separately from camera bodies) shows consistent AF speed regardless of Vbat. Nevertheless, the possibility of a lens negotiating access to higher voltage has not been ruled out.
 * Nikon Pro Bodys have AF-S 8-pin connector for lens interface against AF-S 7-pin on consumer bodys. Example: D3 against D5100. We now know Pin 8 of AF-S interface comes from the lens focus sensor and provides information on the direction of focus change, in addition to the amount and rate of focus change provided by Pin 5 to all bodies. Note, that JPEG EXIF value of focus distance on consumer body is inaccurate and seems to come with serial data.

=Lens Info= Each lens identifies with its own LensID Extensive list can be found at Robert Rottmerhusen LensID pages

Electrical interface: Lens Serial Interface