On Tue, 06 Aug 2002 03:48:42 GMT, "Chuck" wrote:

>Could someone point me in the right direction to learn more about this
>confusing subject.....thanks.....confused Chuckie.

It is confusing. People assume (incorrectly) that their camera (or hand) meters are properly calibrated. This
is rarely true. Meters that read correct exposures in
bright light may not read correctly in dim light (etc.);
few meters correctly read strong colors (particularly
yellow, orange, and red); even meters that are correct
are not often used with an understanding of what they
are telling the user. Assuming accurate aperture and
shutter speed settings (and accurate "representations"
of these in the camera metering systems), and accurate
rating of the film speed used (several popular slide
films are off about 1/3rd stop...) all a good meter
can tell you is how to set the camera to make what you
are metering a middle tone in the image... Add in
"confusers", like spot-metering, "roll-'o-th'-dice"
"matrix" metering, and other error-inducing metering
"features", and it is hard to arrive at really accurate
exposures even if the meter is properly calibrated.
And now, some cameras limit aperture and shutter
settings to the nearest 1/3rd or 1/2 stop, barely
adequate for use with high-contrast slide films.
Best: shut down all the "funny-features" you can, and
expose many frames with a slide film of known speed
(most of the 100-speed films are accurately rated...)
with the best technique you can at the rated film
speed, then shoot more at one notch slower speed, and
more at one notch higher film speed, see what looks
best viewed against a grey-day sky or on a "calibrated"
light table...;-)

[add: aperture true values vary with f-stop, different
functions like shutter-priority, aperture-priority,
program, and manual may not give the same exposures]