Re: [MDOsprey] Binoc problem
pjohn@wlgore.com
Tue, 28 Dec 1999 07:45:26 -0500
Typically this problem is caused by very small amounts of moisture in the
focusing mechanism. This moisture freezes when exposed to the cold air. The
water is condensation usually from bringing optics from a warm moist environment
(your house or over heated auto) into a cold environment (sub-freezing outside
temperatures). The water expands as it freezes and locks up the focus. I've had
this problem with cameras. The best way to avoid this is to keep your
binoculars in a cool dry place and avoid transporting them through temperature
and humidity extremes. When its very cold, I keep my equipment locked inside my
vehicle. To get the moisture out of your binoculars you should pack the
binoculars in an airtight box with a desiccant (not sure exactly where to get
it, but gun stores or chemical supply stores have it). You should not put them
in the oven.
Another potential problem may be the lubricant in the binoculars.
Sometimes with age, the lubricant breaks down and also expands when exposed to
low temperature extremes. This is remedied by sending the binoculars back to
the manufacturer to have them re-lubricated.
In Antarctica fine adjustment instruments have to be re-lubricated with
special low temperature oil to avoid this problem. Even with this, they are
usually left in non-heated places to avoid condensation and thermal expansion.
Parke.