Dew prevention for Dobs in SE QLD

[naskies]

Hi everyone,

As of this afternoon, I'm the happy owner of a new Skywatcher 10-inch FlexTube Dob bought from Sirius Optics :D

Sirius didn't have a collimator in stock, and the scope's collimation was pretty far out to begin with, but I still managed to have a successful first light with my William Optics 4 mm and 28 mm UWAN eyepieces: Orion, Mars, Saturn, Crux, Carina, etc. I was particularly chuffed to see Centaurus A and its dark dust lane for the first time :)

Quick question regarding Dobs in south-east Queensland - does anyone have tips for dew prevention methods that don't require battery power? I like the convenience of Dobs and would prefer to avoid the hassle and expense of dew heaters, controllers, batteries, chargers, etc.

I've searched the forums and it looks like my best bet is to always use a light shroud. I've used the disposable hand warming packs with great success on my DSLR lenses and refractors - are they of any use for a Dob?

Thanks!

[barx1963]

Don't know about SEQ, but here in SW Vic dew is a real problem. I have heaters on everything. The shroud will prevent dew on the primary, but I found I had to put heaters on the finder, the secondary and the EPS to make sure I could even use the scope most nights.

A basic 4 channel Kendrick controller is fairly cheap, but the digifire ones are excellent and easy to use.

Malcolm

[naskies]

Thanks Malcolm! After a few nights of testing in Bris, I've found that my primary/secondary mirrors don't seem to dew up at all but the finderscope and eyepieces definitely do.

I might try using some of those disposable hand warming pads (worked great with my DSLR lenses + bubble wrap)...

[Suzy]

Hi Dave,

I did a thread a while back on dew- there is a ton of very helpful information there that may help you.

http://www.iceinspace.com.au/forum/showthread.php?t=75097&highlight=dew

[naskies]

Thanks Suzy, that's a great thread. Since I started this thread, I've subsequently caved and got myself a dew heater + heating strips :)

My primary and secondary mirrors don't seem to dew up (short of leaving it pointing at zenith for a few hours...), but the eyepieces and finder dewing up was starting to really bug me :lol:

I also calculated that the disposable hand warmers I'd been using for wide field photography was poor value when shooting with multiple cameras/lenses/etc.