The OM-2SP and OM-4Ti measure light through the same two SBC sensors in the
light box during both viewing and the taking of a photograph. When viewing,
light is measured through a semi-silvered section of the main mirror, via
an additional mirror that hangs down from the back of the main mirror. The
semi-silvered main mirror is the cause of some loss of light in the
viewfinder (about 15% ?), which is compensated for by using the 2-13 or 2-4
viewing screens.
Note that this system of light measurement throught the semi-silvered
mirror requires the use of a circular polarizer filter instead of a linear
polarizer filter, to measure exposures correctly in manual mode.
Roger Key
Thanks, Ralf / Roger!
> OM-F/G and OM-40 have a fixed focussing screen.
I do apologize for my superficiality! :( I perfectly knew that!!!
> OM-4Ti does all light measuring in the camera's light box,
> so the focussing screen has no effect on light
> measurement.
The point was just this, for what I knew (I do admit my ignorance!), I
thought that the OM-4Ti / 2SP light measurements, when not in manual / spot
mode, were done with a similar pair of cds cells in the pentaprism as the
OM1/2 do...
Do you have any URL to suggest, for me to know how the OM-2SP/4-Ti auto
metering mode does precisely work (and I don't mean the OTF direct light
measurement, but the exposure time estimate)? It's just for curiosity's
sake...
Thanks again!
Fabio
< 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 >
|