On Fri, Sep 11, 2009 at 4:05 PM, Adam Maas <[email protected]> wrote: > One quibble only, the aperture simulator on K mount only communicates > relative aperture (how far from max aperture the aperture ring is set > to), not the maximum aperture of the lens. It just tells the body how > far stopped down the lens is. maximum aperture communication is only > available on A or later lenses and is electric/electronicly > communicated via the contact pattern of the A contacts and/or the > digital signal pin. > > Nikon's original aperture coupling (the rabbit ears) did communicate > maximum aperture, but that's a relic of it having been originally > developed for the non-TTL metering system of the Nikon F's T prism > which did need to know maximum and relative aperture.
I'll take your word for it. As I said, I'm not entirely clear on the details of the implementation. I guess the "what is maximum aperture" information is no longer needed if you consider "X amount of light hitting the sensor now, N-stops down will hit it at exposure time" and calibrate the positions of the levers accordingly ... Nikon later did the same thing with the later AI system coupling, if I'm not mistaken. -- Godfrey godfreydigiorgi.posterous.com -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
