Tell me something about Dew..

[Worzsel]

I've 'created' a dew shield out of a mat which seems to be the done thing but i've not used it yet, i've not noticed dew when i've been out. I've just wandered out barefoot though to see what I can see and my feet got wet so I suppose I need so start using the shield, i've heard dew is a enemy of the little Mak.

I'll confess my bodged camping mat version isn't great and i'll probably buy one but while perusing FLO i've come accross dew strips so what are they, what do they do, how are they powered and where abouts do they go ?

[Bizibilder]

I think you mean dew heater strips. They are strips that contain a low power heating element. You connect them to your 12v power supply usually via a little box of tricks called a dew heater controller (what else!!). The heater is wrapped around the scope, on a refractor or SCT / Mac etc it goes round the tube just behind the front lens (objective or corrector plate). The idea is that it raises the temperature just enough to stop dew forming on the front of the lens.

You can get (or make) "mini" ones for the finder, eyepieces etc.

For a Newtonian a dew shield is often enough.

[Worzsel]

Thanks Bizi, as I thought it's something ese i'll have to buy

[Psychobilly]

I find its better to prevent it than remove it... I fit all the anti dew kit at the start of the session (shields and heater bands) and run them at a low level all night and boost if neccessary....

Peter...

[Bizibilder]

Worzel - I would put them down your list for buying unless you find dew a real problem. A dew shoeld will often be enough. You can also use one of those "grain filled bags" that are for aches and pains!! Put it in the microwave until it is just warm then wrap around the scope! (That perfume they use on those things is - YUK!!).

[Space Cowboy]

I only use camping mat as a dew shield on my skymax 127...seems to keep moisture off for up to 2 hours.Basically I put the scope out to cool with the dust cap on until I'm ready to observe and then wack the mat on...think mine is about 10 inches long (should be at least twice the length of the aperture size) any longer and it begins to droop.

Walking barefoot in the wet grass is the nearest I will get to dew strips

[Ant]

I agree with Peter completely... Getting rid of dew after it's formed is much harder.

I made a wiring loom (actually 2 looms) for my setup and built into that the dew bands and controller. So as soon as my mount gets power the dew strips are on.

Ant

[IvanT]

I agree with Peter completely... Getting rid of dew after it's formed is much harder.

I made a wiring loom (actually 2 looms) for my setup and built into that the dew bands and controller. So as soon as my mount gets power the dew strips are on.

Ant

Ant, would you post some pics of your shield & heaters please with maybe some specs?

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[Revs]

I was amased how fast the Mak dewed up. On my first night out with it, it was fine until about 1:30am. Over a period of about 10 mins it became unusable and I had to pack up and head home. This was on a warm summer night and I was told it wouldn't dew up until the colder nights came. Wrong! A Dew-Not was my next purchase, which I've wired to a 12v car battery I got from a scrapyard. It'll do several long sessions on one charge and no sign of steamy lenses since!

Accessories @ Modern Astronomy

The 5" one is £28. I also got the 4 channel basic controller, to plug it in to. I fitted some crocodile clips to the controller wires for clipping to the battery.

[Bizibilder]

Dew is like that! It sneaks up on you and then.........WHAM!!