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Path: utzoo!utcsri!hofbauer
From: hofbauer@utcsri.UUCP (John Hofbauer)
Newsgroups: net.rec.photo
Subject: Re: Using lenses in cold weather?
Message-ID: <2208@utcsri.UUCP>
Date: Tue, 25-Feb-86 19:25:17 EST
Article-I.D.: utcsri.2208
Posted: Tue Feb 25 19:25:17 1986
Date-Received: Tue, 25-Feb-86 19:42:45 EST
References: <41600002@hpfcms.UUCP>
Organization: CSRI, University of Toronto
Lines: 19

> What about lenses?  I've read that if I take a lense out in the cold,
> I need to put it in a plastic baggie before bringing it back into the
> warm house.  Is this true?  How cold is "cold"?  Any tips would be

Both cameras and lenses are high precision instruments which are
more sensitive to corrosion than a hammer or screwdriver, lets say.
When you bring something into a warm environment from a cold one
water will condense on it. Recall what happens to your eyeglasses.
The water will cause corrosion and your equipment may stop functioning.
By placing it in a plastic bag and evacuating as much air as 
possible will prevent the warm room air from coming into direct
contact will the cold surfaces and so the condensation will occur
on the outside of the bag. After a few hours the equipment will
have warmed to room temperature and you remove it from the bag.
Don't forget to seal the bag tightly.

The kind of problems that might arise are rusting of the diaphragm
blades and water droplets forming between the lense elements. All
lead to expensive repairs or junking the equipment.