On Wed, 11 Sep 2002 22:49:42 +0200, R�diger Neumann wrote: > The min and max aperture values of a lens were transmited by the contacts of > the KA-mount. A lens from 2.8 - 22 has a certain pattern of the 6 pins. It > is not possible to transmit values like 1.9 in that way. > So there have been a change in the protokoll of the 7th pin which > transmitted the focal lenth and the distance of F/FA lense. It must also > transmit the exact aperture value.
If I recall correctly, either the PK-AF (SMC-F series) or PK-AF2 (SMC-FA series) added a "digital" pin to the lens mount. Since it uses a serial, digital transmission protocol, this pin can transmit anything that the lens and body agree on. I believe that's the way that the FA (and F?) series lenses and bodies provide stuff like showing 1.9 instead of 2.0 in the viewfinder. TTYL, DougF KG4LMZ
