How cold is to cold for a reflector telescope

[Scottbuk]

Hi all

I have recently bought skywatcher explorer 150pl. Just outside the other night and it was around -3c. First night out with the scope so lasted about 2 1/2 hours.

Anyone ever experienced any problems from observing in these temperatures?

Thinking logically about it, I would think a fast change in temperature could possibly cause damage, could be wrong though!

Thanks for any comments

Scott

[moriniboy]

I've never had a problem observing at these temps.

Just make sure you have a good dew sheild.

When you bring it inside the primary mirror is so thick it will take a quite while to warm up, don't stand it next to a radiator though!

[AndyH]

Russian scope maker, Tal, say..............

The telescope can operate normally at the ambient temperature from

30°C to minus 30°C.

I think I'd break at -30 !!!!

[swamp thing]

The Hubble seems to work okay in space. That's pretty cold.

Steve

[Thirdway]

I'm really confused about quite what a dew shield is for? The telescope goes outside to cool for an hour and then we heat it up again? Am I missing something? Is it going on the primary or somewhere else. Excuse the novice.

[James]

I've happily observed outside at -15 and there's no problem for the scope/mount. Your power supply may suffer though if you have one.

When finished I just put the scope/mount in my garage or a shed to warm up gradually the next morning.

James

[Pappy Nick]

According to our local weather forecasts it was supposed to be -6 last night in Bristol. I was out from about 7 until just 9. The 3 inch reflector I'm presently using was white with frost but worked perfectly. The only problem I encountered was my breath condensing on the lens of the barlow and eyepieces and then freezing !!! When I finished, I just left everything in my conservatory, which was colder than indoors but warmer than outdoors

When I double checked all the kit this morning, everything was perfect

CFN

[Merlin66]

I used a 6" f3.6 Cometracker at -40 deg C in Canada some years ago...I needed more protection than the scope!!!

[Scottbuk]

Thanks for the advice people.