Originally Posted by
EdWorkman
Orthochromatic film is green sensitive [in addition to blue]
Early films, such as used by Sullivan, etc, were color blind, meaning response to blue light [only]
The response of ortho film may be slightly modified by yellow 'ray screens'
[which brings to mind the Martian tales of Edgar Rice Burroughs and the 'eight Barsoomian ray]
Graduated ray screens were used to tame skies to some degree
The 1904 Kodak catalog mentions orthochromatic sensitivity, in blurb for its new NC [non curling] film.
Blue sensitive film continued for use for a decade or two after- it was cheaper, just as plates were cheaper than the easier to use roll films and pack films.
Now then, I wonder if there is an available lith film which is really color blind, so that red subjects are rendered black.
[without a red filter factor of 27 stops]
I'm thinking a Pyro developer could tame the contrast.
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