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From: jc@saber.UUCP (John Cincotta)
Newsgroups: net.rec.photo
Subject: Re: RE2485 question...
Message-ID: <1879@saber.UUCP>
Date: Tue, 3-Dec-85 12:45:13 EST
Article-I.D.: saber.1879
Posted: Tue Dec  3 12:45:13 1985
Date-Received: Thu, 5-Dec-85 07:49:34 EST
References: <1750@uwmacc.UUCP>
Distribution: net
Organization: Saber Technology, San Jose, CA
Lines: 18

> Subject: High Speed film question
> Says : jordan@ucbvax.UUCP (Jordan Hayes) - University of California, Berkeley
> 
> * I have heard that in the magazine ASTRONOMY, there are articles on using 
>   chemicals (nitrogen?) on film before it is used to take shots of celestial
>   nature at "very" high speeds. 
the gas used is either hydrogen or a mixture of hydrogen 8% and nitrogen 92%.
the latter is used because there is no fire danger with this mixture.
the film is soaked in this gas for several hours to weeks depending on the
film type. to the best of my knoledge this processing just cuts down on
reciprocity failure of the film on the long exposures that are used for 
astrophotography usually from 10 min to several hours.

Name:	John Cincotta
Mail:	Saber Technology, 2381 Bering Drive, San Jose, California 95131
AT&T:	945-9600
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