cooling down

[dean w]

hi i have just been reading some threads and a couple of people mentioned puting there scopes out to cool down ???? why is this can anyone explain

[perrin6]

Cos air warmed by the mirror will refract light diffently from the cooler air and blur the image like heat rising on a warm day causing a bubbling effect.

[Catweazel]

Reflectors and maks need more cooling than refractors

[Charon]

Rule of thumb is allow 10 mins per inch of telescope diameter.

[Mr Spock]

I try to keep my scope cool by storing it in the porch. That's usually about 5° warmer than outside. Even then I allow at least 45 minutes for cool down.

In the days before I knew better, I had a 140mm Mak which I kept in the living room which had an awful performance. I thought I had wasted my money... until one night I left it outside for three hours - then it started to perform.

[Tinker1947]

My Scope sits in a converted garage, no heating, but no damp, its pretty cold when i lug it to the outside world to try to get it colder..

[Rusty Strings]

Hi and welcome

[telesto]

Hi and welcome to sgl

[LukeSuppalot]

Hi and welcome to the forum.

[dean w]

cheers for that didnt now you had to do that

[todd8137]

Hi there and welcome to SGL

[JamesM]

Hi and welcome to the forum. You might occasionally see some scopes that have been modified to include small electric fans to assist in speeding up the process of cooling. The secret is to keep the scope in as cool place to start with in order to help reduce this delay. Schmidt Cassegrains etc take the longest time of course because they have their glass mirrors contained within enclosed tubes compared with their equivalent sized newtonian type scopes who have a more open set up.

Clear skies

James

[saturn4me]

Hi and welcome to SGL!

[Moonshane]

I was observing the sun yesterday before my scope was properly cooled and as the cooling process continued you could see the image stabilising progressively more each few minutes. until when finally cooled properly the clouds rolled in

[Bizibilder]

It is essential to let your scope get to ambient temperature - cool at night and occasionally warmer during the day if you are observing the Sun (with the correct filters of course!!).

[Moonshane]

It is essential to let your scope get to ambient temperature - cool at night and occasionally warmer during the day if you are observing the Sun (with the correct filters of course!!).

actually, of course you are correct - my scope may indeed have been 'warming' the other day.

[phillc]

Hello Dean and a warm welcome to SGL.

phillc

[mcsheffield]

Hi, Welcome to SGL