> >> I have used the F5 in a snow background
>> and I need not make any compensation for
>> perfectly exposed pictures. The RGB
>> recognises the subject because of the
>> color and differentiates it from the white
>> snow and compensates automatically for the
>> exposure.
> IMO, the F5's color matrix metering works in
> snow, not because it detected color in some
> other thing and differentiated it from the
> snow but mainly because it had a different
> reflectance . . . . The F5 just detected the
> contrast levels from readings in the different
> segments and calculated the exposure.
Not exactly. You're correct that color probably
isn't required to reliably detect snow -- the
F100 would probably do as well -- but the F5
doesn't consider color, reflectance and distance
separately. Strictly speaking, it doesn't
'calculate' exposure at all.
It considers all of the data at once and attempts
to match the pattern in the data to the pattern in
a scene that it's seen before (one that's in the
famous 30,000 image database). Then it just uses
the exposure compensation value that was used for
the 'remembered' scene that matches most closely.
-Don
