Dew shield

[JonnyK]

So after bugging everyone on here I have a celestron 127mak on it's way over to me. I ordered the power cable and dew shield unfortunately the dew shields are on back order. Would I be ok using it without untill it turns up?I've seen on here that people make them out of camping mats?What kind of material would be best?Are they like a neoprene kind of material?

[rowan46]

neoprene would I think be a little floppy it needs to overhang your scope by 1.5-2x the apparture ie 7.5"- 10" camping mats are available from many of the supermarkets or discount shops and only cost a couple of quid get yourself a nice dark one. Nb the thicker neoprene would probably work ie the 5-6mm one

[nightfisher]

Jonny, have a look at the dew shield on my 180 mak, see equipment gallery, mine is made from a black vinyl sheet and flocked on the inside, its better than one you can buy. its a push fit over the end of the scope

[M4lcs67]

With the onset of spring/summer the nights should be warmer and to that end you may not need the dewsheild yet anyway. I got my 127 slt exactly a year ago and did't get the dewsheild for a while after. So if they are on back-order I would get your order in, but you should be alright in the meantime.

[umadog]

Even cardboard will work. As I understand it, the dewshield reduces radiative heat loss by reducing the area of sky to which the corrector is exposed. So that's what you're aiming to do.

You see this radiative effect in action on the outside of the telescope: the upper part of the tube dews up more quickly than the sides, which in turn dew up more quickly than the underside.

[Astrosurf]

Jonny, have a look at the dew shield on my 180 mak, see equipment gallery, mine is made from a black vinyl sheet and flocked on the inside, its better than one you can buy. its a push fit over the end of the scope

Can you provide a link? Ta muchly.

Alexxx

[Tinker1947]

I used Cell Foam, 5mm thick, tape into a tube with black duck tape, cost a fiver for my 10" tube....

[Northern Soul man]

Hi Ya Jonny, I've got the 127 Mak and just made 1 out of 1 of my lads plastic folders which he stored a4 paperwork in, it has thin see through sheets in it, just ripped all the sheets out of it, folded it around the tube assembly - nice fit - unrolled it again, covered the inside of it with black tape, folded back around the tube, taped it up and a perfect push fit over every time, mind, with these hot nights the seeing and sky conditions tend to be quite poor, the cheapest I could find a camping mat was about £5 - the folder was just lying around, my son, not even noticed - mind you he likes astronomy about as much as I like that drum and base dub step thingy ( you get the picture). Paul

[jonathan]

For a quick, cheap option I agree with the card - a large piece of black stiff paper would also do the trick. Just wrap it around the end of the scope to make a tube then tape it up down it's length, I did this before I bought an AstroZap dewshield (which are very nice btw), the card may not last very long though as it will get wet if there's a lot of dew about.