As I understand it, the matrix metering algorithm on the MZ cameras requires
the absolute light values measured by the cameras metering segments. An MZ
body with and A, F, or FA series lenses mounted to it knows the value of the
wide open aperture and can therefore calculate the actual scene brightness
levels measured by each metering segment. A K or M series lens does not
transmit the value of the wide open aperture so the camera body would only
know the relative brightness levels of the various metering segments. My
understanding of the MZ cameras is that if you mount an M series lens the
metering mode automatically reverts to center-weighted. It would seem to me
that the designers could have implemented a slightly less effective matrix
metering algorithm for M and K series lenses. Probably they didn't want the
expense of developing two algorithms or maybe they did and it wasn't any
more effective than center-weighted metering.
This would have been an interesting pentax function for the MZ-s ... allow
the user of an M or K series lens to select an open aperture value to be
used by the camera for matrix metering if no value is transmited to the
camera by the lens.
Well ... I'm starting to ramble....
Eric
>From: Frank Wajer <[EMAIL PROTECTED]>
>Date: Thu, 6 Sep 2001 14:12:23 +0200
>
>Does anybody have an answer?
>I don't understand why having an automatic aperture influences this.
>
>Frank
>
_________________________________________________________________
Get your FREE download of MSN Explorer at http://explorer.msn.com/intl.asp
-
This message is from the Pentax-Discuss Mail List. To unsubscribe,
go to http://www.pdml.net and follow the directions. Don't forget to
visit the Pentax Users' Gallery at http://pug.komkon.org .
