> No, there's a good reason for it: The matrix metering algorithms need 
> to know not only the maximum aperture of the lens (which it gets from 
> the ID Insulators, but also the actual shooting aperture, which it can 
> determine from the non-linear movement of the diaphragm actuator arm on 
> "A Series" and later lenses.
> 
        Ah... my bad.  The cause/effect is a bit off though, no?  The 
non-linear movement of the diagphram arm is what the *body decides* to do 
if A or later.  The shooting aperture is determined from the aperture 
simulator in K/M/A-in-non-A.

        I still say the "green-button" trick could be made to work better 
and allow these things, even without the aperture simulator.  If one could 
manually set the max aperture of a K/M lens, the body would know.  Hitting 
the green button could then be used to compute the *difference* between 
wide-open and shooting.  Then you'd only have to hit the button if you 
change the lens aperture... not if the lighting changes.

-Cory

-- 

*************************************************************************
* Cory Papenfuss, Ph.D., PPSEL-IA                                       *
* Electrical Engineering                                                *
* Virginia Polytechnic Institute and State University                   *
*************************************************************************


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