ddb@mrvax.DEC (DAVID DYER-BENNET MRO1-2/L14 DTN 231-4076) (10/01/84)
One approach is to meter the snow, then open up three (or two) stops
("Place the snow on zone VII (or VII)" in zone system terminology).
This should give you snow that just barely holds detail. This is
excellent if the snow is the main subject in the picture.
Another approach is to meter close-up the main subject, and place
it where you want it; this can leave you in the position of having
large parts of your picture glaring white, if the snow ends up falling
too high on the scale. In general I have not been satisfied with any
fixed exposure adjustment; the required correction varies too much
with the situation and my intentions (this is one of the reasons I don't
use an auto-exposure camera).
Incidentally, if you're shooting snow/skiing pictures, and particularly
if you are at high altitude, you probably want to use a UV filter for the
unusual purpose of removing UV (far more often they're used to protect the
lens), since the snow will reflect UV, and at high altitude the atmosphere
doesn't cut as much of the UV, potentially leaving enough to affect
exposure and/or color.
(oops, in the first sentence, the first reference to zone VII should be to
zone VIII)
-- David Dyer-Bennet
-- decwrl!dec-rhea!dec-mrvax!ddb