Richard M. Koolish (koolish@bbn.com)
Sat, 20 Feb 1999 19:04:24 -0500 (EST)
Cold cameras for astronomical use with film were produced commercially.
I think the originator was somebody named Williams, and the camera
were eventually sold by Celestron. They had a clear plastic plug to
keep the film from being frosted, and the film was held in place
against the plastic plug by an aluminum block and cooled by dry ice.
As I remember, it worked by reducing the reciprocity failure. Through
the years, astronomers, both professional and amateur, worked on a
number of techniques to hypersensitize film. Baking in a hydrogen
atmosphere seems to be the most common technique these days, with
hypersensitized film being sold by Lumicon. I used some hypered
Tech Pan for some shots of Comet Hyakutake a few years ago.
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