Outside Temperature and Scopes

[Star-Gazer]

Hi

I am at home with my scope outside and I am noticing what looks like ice coming and I don't know whather scopes can be out in such cold - anyone advise please - asap if poss!

[Star-Gazer]

brought it in.

[RogerTheDodger]

A few nights ago there was a chap in one of the scandinavian countries out in -21c, I think you'll be ok

[steviet]

A temperature related question - When cooling the telescope down do you leave the Cap on or off?

[MorningMajor]

A temperature related question - When cooling the telescope down do you leave the Cap on or off?

I leave it on to keep dew off it - can't think it makes much difference to the temperature of it - but, please prove me wrong

[John]

Depends on the scope for me - newtonians = cap off so that the warm air escapes out of the top of the tube, refractors, maks, SCT's = lens cap on but eyepiece plug out and scope pointed downwards to let the warm air out of the tube through the diagonal.

Heat also radiates away through the tube walls as well.

[brianb]

I am at home with my scope outside and I am noticing what looks like ice coming and I don't know whather scopes can be out in such cold

No problems with cold, condensation can be a problem but the temperature isn't. The scope will definitely stand anything I can!

[MorningMajor]

Depends on the scope for me - newtonians = cap off so that the warm air escapes out of the top of the tube, refractors, maks, SCT's = lens cap on but eyepiece plug out and scope pointed downwards to let the warm air out of the tube through the diagonal.

Hadn't thought of Ep out to let air through diagonal - thanks for that John