At 23:54 6/10/02, you wrote:
Oh. So.... Why did the Yellow Father name the film after its P2 speed,
breaking tradition? I thought films were always, I mean ALWAYS named after
their nominal (ASA in the olden days) speed. By this insane naming
convention, Tri-X is now "Tri-X 1600". How does that help anyone?
Pondering a class action suit..... :)
Lamadoo
If I've interpreted the data sheets correctly for Plus-X, Tri-X, and all
three of the TMax films, all but P3200 are designed to be used and
developed normally at their named speeds. They can be pushed, but the
emulsion isn't designed for it and one pays a price in graininess and
contrast increases knowing the film was not specifically designed to be
used at higher speeds. Supposedly (and I haven't tried it), Tri-X in
particular works OK pushed with contrast if one can accept the grain increase.
What makes P3200 different is its multi-speed emulsion that is specifically
designed (intended) to be used at EI 3200 with P2 processing. I haven't
played with B/W much, so a lot of this is derived from reading the data
sheets and looking at the response curves at nominal speed ratings and
comparing them to the published curves when they are pushed.
BTW, Fuji did the same thing with Provia 1600. Its nominal ISO rating is
400, but it has an emulsion very different from Provia 400. It is also a
multi-speed film that was designed to be pushed and for its characteristics
when it is (versus using it at its nominal speed).
-- John
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