Jim, look at Boz's site. The Pentax contact layout uses 6 pins as a coded max/min aperture info(6 bit digital code, 3 bits for max aperture, 3 bits for minumum), one to indicate whether or not the lens set to A and one as a signal line. The latter only exists on F or later mount lenses and KAF and later mount bodies and is the only contact involved in any communication between the lens chip and the body (the mount itself is ground). The two pins inside the mount on KAF2 bodies are power for Power Zoom and SDM lenses.
-Adam jim wrote: > On Wed, 15 Aug 2007 09:36:01 -0500, Charles Robinson wrote: > > Not a pin as such no. Camera comnunication with lens is some form of serial > protocol. > The DIGITAL pin I believe is power for the lens chip. The r3, r2 and r1 > contacts are for the serial bus of some form. > A1 and A2 aren't used tho these new SDM lenses may use these pins as well > (focus?) > Info passed would be lens type number, focal length, zoom position , MTF and > what ever else pentax has decided to add. > Covering one digital pin will kill all the above info transfer so chances are > lens won't auto focus either. > > I cannot prove any of the above unless some one has a multi input logic > analyser and data logger. > Got all of this from pulling apart a sigma lens, using a logic probe and some > guess work. > > james > > >> Isn't there a pin/contact/whatever somewhere on the teleconverter >> that you could cover with tape so that it did NOT pass focal-length >> information? > > > > > -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net
