Archived posting to the Leica Users Group, 1997/11/16

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Subject: Re: Many are Cold, Few are Frozen
From: Dan Cardish <dcardish@microtec.net>
Date: Sun, 16 Nov 1997 16:15:52 -0500

>>
>>In astronomy they sometimes use special cameras in which the emulsion is
>>chilled with liquid nitrogen. I was under the impression that film became
>>more sensitive (presumably to both visible light and cosmic rays) at very
>>low temperatures. Do any of the amateur astronomers on the LUG know
>>anything about this? 
>> 
>
>I'm not sure about what you mentioned, but the super-cooled instruments 
>are used in astronomy are typically composed of electronic sensors, not 
>film emulsions.  [snip]

Cooling photographic emulsions helps eliminate reciprocity failure when
making long exposures of very faint objects.  It doesn't necessarily
increase the sensitivity of the film, though it may appear to do so.

Dan C.