Is Moisture Harmful to Telescope Lenses in Cold Weather?

[redrum781]

i just bought a telescope and i am in Canada it iz really cold outside and i want to take it outside to look at the stars but someone told me that moisture would get stuck in the lens and it would be ruined can somebody tell me if this is true personally i don't think it would but i don't want to take a chance of ruining it right away

 

[ray b]

no it should not ruin the lens
if you can put the scope in a place that it will cool befor you go out to use it
like a garage or in a car as the hot scope will attract water from cold air
that will make it hard to see thru it

most good seeing is in cold clear weather so everone has this problem

a cover called a dew cap is a good idea too
or you can cover the whole scope with a plastic sheet
when waiting for it to cool

 

[russ_watters]

I have a relatively new Meade ETX-105 and have used it in cold weather (about 15F). One problem (besides frostbite) is the adhesive holding the diagonal flip-mirror in place loses its stickiness and can fall off. Its not difficult to fix yourself if that happens, but it was scary/annoying for a new scope to have that problem.