>
> In a message dated 6/25/01 1:32:16 PM Central Daylight Time,
> JohnFarrias@msn.com writes:
>
> << to joebesse@aol.com-this is john,astronamers use hydrogen gas -the welding
> type for exposures up to 10 hours with no reciprocity problems.i'm putting
> together a small aperatus to test this for pinhole work .
> >>
> I have heard of gas hypersensitizing process a long time ago, and I too have
> been looking at how to acquire the films, is this something you must do
> yourself, (the hypersensitizing ) or are the films available at retail source
> or outlet ? I know of one photographer (Stephen DiRado ) who has works posted
> on a web site, he does night photography, and from what I can tell he must
> use the gas hypersensitized films . If any one is interested in obtaining the
> URL for his works, they can email me off list
>
> DAlfrey@aol.com
There are actually a number of different ways to hyper-sensitize film.
Astronomers do this because they make long exposures under low light
conditions and reciprocity failure is a big issue. The most common
technique uses hydrogen gas, either pure (which is explosive) or
in a non-explosive mixture called 'forming gas'. If you do a web
search for the phrase 'film hypering' you will get a number of hits.
Lumicon (www.lumicon.com) sells hypering kits and also sells a number
of hypered films, some 35 and some 120.
Received on Mon Jun 25 15:31:17 2001
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