Cold Scope - Dew Heater Quandary

[BargeGazer]

OK, so I must let my telescope cool down. But what if, as is common for me at the moment (I am very near a lot of water) Dew is a problem.

An anti-dew heater seems to fly in opposition to the keep it cool philosophy.

Which way do you go?

AND how do you stop dew forming on your eyepieces, even when not in use. This is causing me to have to stop observing after an hour or so at the moment (around 12:30). As I noted, I am by a river so humidity is high. Maybe I just have to move a kilometre or so away!

Scope is a Skywatcher 127 Mak' Cass'.

[Alan_B]

Dew heaters are an essential piece of kit here in the UK so I guess similar applies to France

As for the eyepieces - keep them warm , I tend to put them in pockets in my fleece/coat/jacket

[Prador]

A dew heater tape is designed to keep the lens/mirror just above the temperature at which dew will form. If you go down the heater tape route don't max it out otherwise it may affect seeing. Get a decent dew heater controller and use it to regulate the power to the tape to maintain a few of degrees above ambient.

When I am out observing I keep all my ep's in the case until I need them. A pain?, yes but it does help to delay the onset of dew formation and ruin any views.

Dave

[swamp thing]

In a way.Yes, the dew heater goes against everything you are trying to achieve by letting the scope cool down but at least it allows you to carry on observing when without it you'd be packing up for the night. It's the better of two evils really.

[Darkstar_1]

I keep my eyepieces in a padded case along with a couple of small bags of silica gel. It seems to help by absorbing moisture in my case,

[jonathan]

A dew heater shouldn't necessarily prevent your scope from cooling down, the heat that you are trying to get rid of will be coming from the bulk of the body and the heater tape should only be heating the very end of the telescope body, which is a very small part overall.

I have had bad nights with dew ruining otherwise great evenings for viewing, I have purchased dew heater tapes for my finder scope, OTA, and eyepiece now, I will be running all of them when dew is evident so I'm hoping to have a mains option this winter! I have two battery packs as it is, but they are a pain to lug out when I'm just in the back garden and within reach of a mains supply.

[faulksy]

you can make your own heater system like i did. i now have heater bands on my collector my diagonal which transfes to mt e.p. and i have them both ends of my finder scope and i have never had a problem. cheap way is a 12v hair dryer and just give everything a blast now and then

[LukeSkywatcher]

Dew heaters are placed around the objective,mirror which is at the front end of the scope. This prevents dew from forming on the objective,mirror. As warm air rises (cold air falls), this will keep the optics warm enough to keep the lens/mirror clear and it wont send any warm air down into the already cooled scope tube.

[BargeGazer]

Thanks everyone. Nice to know it isn't just me getting everything wet! I will try the dew shield and warm pockets for the eyepieces first before I go the tapes and extra power supplies route.