Author Topic: A few newbie questions.  (Read 1318 times)


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A few newbie questions.
« on: September 21, 2015, 08:53:01 AM »
Aaaargh! Stupid computer deleted my entire post..... deep breath and try again!  :P

I managed to view my first, absolutely 100% certain deep space object on Friday night, The Ring Nebula. However whilst oogling at this tiny grey smoke ring in the sky, I became aware of a couple of issues so thought I'd ask here for advice.

I put the scope out in the back garden around 8pm (just before the rugby kicked off), and didn't sit down to start viewing until around 10.30pm, thinking this would give the scope (Skywatcher 200p), plenty of time to equilibriate. During this cool down period, I left all the covers in place. Should they be on or off?

Whilst viewing, I quickly became aware of dew forming on the lenses. Is it okay to use lens wipes to clear this away?

Finally, when storing the scope away for the night after a viewing session, I replace all the covers before bringing it inside, but afterwards, once the scope has warmed up again, should I remove the covers to let the air exchange, or does most of the moisture condense on the outside of the scope?

Cheers for any help!



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Re: A few newbie questions.
« Reply #1 on: September 21, 2015, 09:07:41 AM »
20 to 30 minutes should be long enough for that scope to be ready to use, so put it out at half-time and you're good to go by the final whistle.
It will get some extra time to cool while you align everything or when you are looking at your first couple of objects.
Remove the covers, but don't point it up at the sky until you're going to start using it (you could get dew forming before you've made a start).
Whatever you do storage-wise, try to avoid extreme changes in temperature (e.g., I keep my scope in an unheated cupboard in the house, but loads of people keep them in the garage or shed, where it remains closer to working temperature).
As for wiping lenses, try to avoid doing this.  Get dew heaters or a small portable hair dryer.  When using the hair dryer, use the lowest speed possible to clear it.
If the outside of the scope gets iced up or wet, it's worth trying to dry it off before storing or leave the outside cover off until this has dried off.
The cover that protects the mirror should be put on as soon as you've finished observing.
Hope the above helps, although I can't claim to be an expert in these things.
Sky-Watcher Skyliner-250PX FlexTube Parabolic Truss-Tube Dobsonian with Baader Hyperion 36, 21, 13 and 8mm EPs and a 2x Barlow.
Telrad and RACI finder scope for finding objects the good ol' fashioned way:-)