Uses for a foam rubber ground sheet

[JulianFR]

I found a foam rubber ground sheet, for putting under a sleeping bag. L think I read somewhere that this could be used somehow with a telescope, to reduce dewing. Does anyone have any suggestions how I could adapt the ground sheet to keep the dew away, by cutting it up or whatever?

Thanks.

[astronymonkey]

For the 200p dob you have you can make a tube from it to fit on the end of the scope tube. This will stop any stray light from reaching the secondary and focusser,  which in turn reduces contrast, but it also reduces the chances of dew being able to settle on the secondary which basically ends a nights viewing unless you have some for of dew contro

Cheers

[knobby]

Google DIY camping mat dew shield , brings up loads of people's tutorials of cutting sticking sewing gluing etc. rough guide is to make it 1.5 times the diameter of the telescope. Good luck

[itmo]

I made a dew shield out of a camping mat  (works well) , but I also experimented with cutting up a piece of it to fit the backside of the secondary mirror. Seems to help with dewing quite a lot. 

[JulianFR]

Many thanks for the advice all.... I'll look into this over the holidays. Though at this rate I'm not expecting clear skies any time soon :-O