>From: Winsor Crosby <wincros@xxxxxxxxxxxxx>
>
>I am not sure how the meter knows what the F-stop of the lens
>that is attached.
It does not. It only knows a relative change from wide open. The open-aperture
meter sees the light of the open aperture, then corrects it for how many stops
difference the lens is set from full open. (This is distinct from the TTL
metering, which only sees the light of the taking aperture, NOT the full-open
aperture.)
This is (IMHO) a weakness of the OM system. It precludes showing actual f-stops
in the viewfinder, for one thing. On the other hand, it allows T-mounts to work
with ANY lens, regardless of the full-open aperture.
>Could it be some linkage variability in 30 year old
>lenses that have never been CLAd?
As long as you are metering full-open, there should be no problem. If you are
metering stopped-down, there MAY be some inaccuracy in what the lens is
reporting to the body.
--
: Jan Steinman -- nature Transography(TM): <http://www.Bytesmiths.com>
: Bytesmiths -- artists' services: <http://www.Bytesmiths.com/Services>
: Buy My Step Van! <http://www.Bytesmiths.com/van>
< This message was delivered via the Olympus Mailing List >
< For questions, mailto:owner-olympus@xxxxxxxxxxxxxxx >
< Web Page: http://Zuiko.sls.bc.ca/swright/olympuslist.html >
|