Re: PHOTO-3D digest 1603

[P3D <dlevy@xxxxxxxxxx>]

>While the overwhelming majority of Adam's life work dealt with B/W, his
>observations concerning reflectance, it's measurement, and how it
>relates the the contrast ranges of photographic materials is I think
>quite relevant to the proper exposure of slide film. In a world where
>deep black clothing reflects 3-4% of incident light, and white white
>sands up to 96-97%, do we compensate? If so, how do we know how much?
>How do we deal with yellow sand beaches versus white sand beaches versus
>snow scenes?
>
>
>
>Eric G.
>
Guess what? You just used the zone system. W/ transparencies as opposed to
neg., you expose for the highlights and let the lowlights fall accordingly.
Actually, this is to a user of the zone system that you look for the most
significant highlight where you want to retain detail and expose it so it
will fall into about zone vii - viii. If it is actually a zone ix which on
film records as white, you have adjusted the ev by 1 stop. Hence the zone v
reading would now read zone iv. I have found that most shooters do these
adjustments without relating them to the zone system. The development of the
system was to be able to quantify and communicate this evaluative process to
others. For the initiate, it sounds confusing, but once integrated with what
you know, it is old hat. After awhile, one does not even think about it
since it in turn becomes second nature. 

The system is most flexable with sheet film because of the development
controls, however that is an extension of the basic system. Therefore it is
usable even with rollfilm whether b&w, color or transparencies. Another way
to reconcile this is to consider development controls. In b&w work we talk
about N-1, N, N+1, N+2. This is nothing more than saying 'pull', 'normal',
'push' and 'double push' color or transparency processing. Same horse,
differnt view.

Brian Levy, J.D.
Toronto, Ont.
dlevy@xxxxxxxxxx


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