Dew Heater/ Dew Shield

[Stryda]

Hey guys again!

Firstly merry xmas to all!

Secondly, Im in need of some dew prevention for my 8" LX10.

What's everyones views on the best solution? A dew heater/strip or a dew shield? Pros/cons?

Also if anybody could point me into the right direction for buying either of these it'd be very helpful.

Thank you

[brantuk]

Dew shield for definite. If thats not enough then you may need a heater system including a controller and one or two strips for the corrector and/or the primary. Some people use one for the ep as well but keep your ep's in your pocket and it might not be needed. A selection of dew stuff can be found here:

Dew Prevention

[Stryda]

Thanks for that!

Is astrozap a good make for dew shields? Have you or anbody else got one?

[Leegsi]

I have one on my Skywatcher 150 and it fits and works really well.

[Brinders]

Thanks for that!

Is astrozap a good make for dew shields? Have you or anbody else got one?

I use an Astrozap dew shield on my CPC925GPS and I can say it is certainly of better quality than the Celestron one I had for my previous scope. However, I find that a dew shield only offers limited protection, especially if the scope is pointing towards the zenith. I also use the Dew Not system (heater strip on the scope, towards the correcter plate end, and heater controller). I don't find it necessary to use a heater strip on the eyepiece: the warmth of your eye keeps the dew off and I always replace the cap when I have left the scope. Similarly, replace the caps on the finder scope as soon as you have finished with it.

Brinders

[Stryda]

Thanks, I may have to have a stab at buying one

[Demonperformer]

Try a piece of black card wrapped around the end of the tube. That's what I use, although I have now strengthened it a bit with 5mm foam mat. Really cheap and have never had a dew problem since I started using it. There is a piccie of it in situ in my album "6SE".

HTH

[dlp]

I followed many others' advice and used a cheap camping mat (about £8). I placed a piece of paper ribbon around the end of the OTA and pencilled a cut mark. Then rolled out the mat and used the paper to measure where to cut with a Stanley knife and bevel-edged metal ruler. I spread contact adhesive on the 2 edges, waited to dry, then the difficult bit of mating the 2 edges together when in a springy circle! As the cut edge wasn't exactly 90 deg everywhere, I ran some masking tape up the outside and folded over the ends. It works a treat on my reflector, and also helps stop light from street lights spilling directly on to the open end of the OTA. One thing I have to remember is to attach the tube before mounting the OTA on the mount as it's a snug fit and needs some pushing. You don't want the scope turning the gears of the drive after you've polar aligned.

I also made a very simple shield for my Telrad by just folding some thin foam into a 'U' shape and attaching with velcro dots. I haven't been troubled with dew since doing these things, and I've finished some nights with a layer of ice all over the scope.

David

[michael.h.f.wilkinson]

I just got a Celestron dew shield for my C8 as a present, and could use it the same night . It was very cold, and a lot of hoarfrost formed on the dew shield during a 3 hr observing run, but none on the corrector plate

I am really impressed with the effect of such a simple device, on a night that would otherwise have had me reach for the hair dryer several times.