Cool Down Time

[Star-Gazer]

Can someone please tell me what the cool down time for my SW SM127 is and also tell me where they got the info from.

[Cunhaval]

Hi,

There is no set cool down period. Depends what temperature the scope has been stored at (warm lounge or cold garage) and what the outside temperature is (January or July).

If it helps, my 127 takes only about 30-45 minutes at worst in January, when I make sure that it's stored in the cool garage, and a little less in summer. Best to try and make sure that there is the minimum difference between storage conditions and outside conditions, if you can.

That said, some people report much longer cool down times

[Nexus 6]

my cpc 925 takes around an hour or even more during the colder months, would have thought for your 127 at least half an hour. As already mentioned the temp were its stored is critical, mine is in the conservatory so although its warm in there once I open up the doors I can leave it for bit before putting it in the garden, just in case it rains.

[brantuk]

To get a good estimate for your scope - start using it as soon as you're outside and set up. Take note of the view quality - then leave and go back to it evry 15 mins or so taking note of the quality of view. Soon as things start getting crisper and clearer you'll have a good idea roughly how long it takes and will know for next time

[RikM]

Mine takes ages to cool. At least an hour, possibly up to 2 hours but that could be due as much to darker sky as cooldown. The problem is, I have run out of storage space so the Skymax lives in a padded hold-all on top of the wardrobe in the bedroom.

[MorningMajor]

Usually like to give mine an hour - unless I get really impatient!

[GeorgeB]

I don't bother with cool down time; I just use it straight away as soon as I take it outside. Any theoretical improvement from bringing the optics to a thermal equilibrium is completely wiped out by my urban London viewing location.

[dweller25]

I used to own one and it took around 1 hour from 20'C to 0'C - centrally heated house to mid-winter outside.

You can tell if it's not cool - defocus on a bright star - if you see lots of wriggly worms on the doughnut shape then it is not cooled.

It will cool much quicker if you unscrew the front corrector housing first.

[kniclander]

a lot also depends on what power you are using. at lowish powers you probably won't notice anything unless you take it from the oven. even at high powers it's fairly subtle and, as someone else said, atmospheric instability may well be the limiting factor.

[wrinkly]

a lot also depends on what power you are using. at lowish powers you probably won't notice anything unless you take it from the oven. even at high powers it's fairly subtle and, as someone else said, atmospheric instability may well be the limiting factor.

"From the oven"?

S'pose it saves getting cold fingers but don't baste it.