That requires a linear aperature mechanism, which only A and later
lenses have (That's one of the major changes between K/M and A lenses)
-Adam
Gonz wrote:
See my earlier post:
"Pentax could have had a pseudo-AE mode if they wanted to with just one
press of the green button per aperture selection if they wanted to. By
taking two measurements, one wide open, one with the aperture down, a
simple ratio could be used for all future calculations using the future
wide open measurement. If you changed the aperture, you pressed the
green button again. "
rg
Shel Belinkoff wrote:
How might the "green button" be improved?
Shel
[Original Message]
From: Gonz
I'm glad Pentax implemented the green button though of course, but
they could have done a better job of it.