Dew

[MYLUCKYSTARS]

I've noticed recently that dew has been building up on my scope & eyepieces as well as my binoculars. I noticed that it can leave condensation. Is this ok for the scope & binoculars? & how should I deal with it? Also is frost in the winter bad?

[fwm891]

In the absence of heater bands then a hair drier is the standard 'tool'. A warm airflow rather than a scorching heat is best.

Open tubes suffer more than closed ones so a shroud of some sort helps.

[Bart]

I've noticed recently that dew has been building up on my scope & eyepieces as well as my binoculars. I noticed that it can leave condensation. Is this ok for the scope & binoculars? & how should I deal with it? Also is frost in the winter bad?

The dew and frost won't harm the optics, just allow to dry off naturally.

I use a hairdryer as I hate having a big shield hanging off the front of the scope.

Barry

[m37]

dew tapes help a great deal, not exactly cheap though. a tape and controller is getting on for £75.

[Daddystu]

I came in the house to run my setup last night and I fell asleep for 4 hours! I woke up at 5 am and everything was completely covered in dew. Soaking wet. All extension cables - laptop screen and keyboard. However, ethereal dawn had brought with her Orion in all its majesty so I capped off a few M42 subs before drying and packing away. I was a little surprised everything worked and I didn't get an electric shock though.

[IanL]

Try these:

Dew theory: http://www.blackwaterskies.co.uk/2013/05/dew-formation-and-prevention.html

DIY heater bands: http://www.blackwaterskies.co.uk/2013/05/making-your-own-nichrome-dew-heater.html

Ultra cheap dew heater controller (£5 - £30 depending on what you want, not £75 quid!): http://www.blackwaterskies.co.uk/2013/05/a-cheap-multi-channel-dew-heater.html

Head over to the DIY astronomer section for more advice on building them if you need help.

[AlexB67]

I've found my desiccant dehumidifier to be very handy for astro equipment. It works a treat. Probably one of my more expensive accessories, though it was never bought for that purpose at the time It seems so much more efficient compared to the traditional refrigerant dehumidifier type I had before when it gets cooler in evenings. I put all my eyepieces and scopes not too far away from there in the boxes with the lid sort of half on ( so no dust falls on them too quickly) when I get in. The lot is nice and dry in minutes and then get put in their boxes.

[TwoPi]

Regarding the eyepieces, I learned the hard way that resting them on the scope mount base (or in my SkyWatcher's eyepiece rack) lens up with no cap on is a recipe for dew!

I have an old camera bag with little compartments in it that I use to store them, so I just pop an eyepiece back in the bag when I take it out of the focuser and as long as I close the camera bag it seems to do the trick - no need to put the caps back on / put them back in their individual cases during the session.

That combined with a light shroud on my flex tube has meant no significant problems for me so far, but we'll see when the autumn comes whether I need to start nicking my wife's travel hairdryer...

[jason.p]

At the moment I use a hairdryer (I have my own now;)) and keep the eyepieces in my pockets where body heat keeps them free from dew. I do have a clean coat just for observing. I learnt the hard way not to use my regular one where the pockets are full of brickdust:o

I think I'll have a go at the dew band controller described in Ian's links.

Sent from my GT-P5110 using Tapatalk 2

[Bart]

How about adding a dew shield for the eyepiece holder at the side. It's a piece of camping map attached above the holder. No dew on EPs at all !! Just leave enough space above for the big'uns!! When I did it, I didn't have the 100* fellas!

Barry

[TwoPi]

Interesting idea Barry, hadn't thought of something like that. Might give it a bash - cheers!

[cotterless45]

I keep my eyepieces in a warm clean jacket and trouser pocket. This keeps them just warm enough for keeping dew away.

I've never had dew problems on Newts and use dew shields one and a half times the diameter in length.

Refractors seem to be a dew magnet and it's either hair drier time or remembering to fit the dew band on beforehand.

Found far less dew observing on the patio compared to open grass,

Nick.

[Viewmaster]

Funnily enough only this morning I ordered 300 x 600 ohm resistors on ebay for £3. Any of my outdoor items likely to dew will be adorned in a necklace made from them. Bunches of these R's wired in parallel across a 12v supply (variable for each necklace) so each R will run at 1/4 W or less . I therefore will have a maximum of 75 watts available if all were used up!!........might wire up a few in my gloves too .....just kidding. I also have 2 digital rotary angular readouts which should never be used below 4 C so they will get the same treatment.

[AlexB67]

When observing on a grass surface a camping mat may be handy, it may help. With my small dob if I put it anywhere near the ground dewing happens much more quickly, as you may expect. Equipped with all that dewing equipment, all you need is a stereo and play a tune like this

http://www.youtube.com/watch?v=3SYwq0K7-D4&feature=related

and all your worries evaporate instantly, along with any water molecules dancing to it in harmony

[Bart]

Interesting idea Barry, hadn't thought of something like that. Might give it a bash - cheers!

Cheers Gav, its simple and ALWAYS works.

[Bart]

When observing on a grass surface a camping mat may be handy, it may help. With my small dob if I put it anywhere near the ground dewing happens much more quickly, as you may expect. Equipped with all that dewing equipment, all you need is a stereo and play a tune like this

http://www.youtube.com/watch?v=3SYwq0K7-D4&feature=related

and all your worries evaporate instantly, along with any water molecules dancing to it in harmony

Fine piece of music.