Dew covers

[bcfcciderhead]

Been reading a lot on here about "dew", from what i can make out this is a big problem and with the nights getting colder can be an issue with most of us, more so me as i go spotting 2 miles away so taking the scope from the car to outside may be a problem?.

I see you can get "dew covers?" i'm guessing these are little jackets to go around the scope? if so are they worth getting?

At the moment to transport my scope i wrap it in one of those padded sleeping mats, if i was to make this a little better fit would this do the same sort of job?

Also seen that fans are the way forward but not to willing to go drilling holes:eek:.

So just to be sure these covers are to help insulate and reduce the cold air from getting into the scope?

[resonator77]

You can make your own dew shield with camping mat, just make it twice the size of your scope aperture to be effective. I do not think you would need a fan installed with your telescope, it is small enough to cool down to ambient temperature in 30 min to an hour.

[haitch]

Although you can get dew on a newt it's more of a problem with the type of scopes that have a lens or corrector plate at the front.

In extremely dewy conditions you can get dew on the secondary (I think I remember suffering it about twice in the last few years) but a dew shield made out of camping mat should stop that. Dew heaters or fans shouldn't be necessary to stop dew on your 130p although when not at the ep you could always drop half a bolt tube over the ep to slow the dewing down on the EP lens.

Your finderscope will be more of a problem. My rdf suffers badly but still works as I see past the glass with my other eye and so can still see the point in the sky it is pointing at.

You don't want to keep cold air out of your scope as having your scope at the same temp as your surroundings will help the views. You get dew when the optics of your scope fall below ambient temperature and dewpoint because they are radiating heat energy out into space.