DIY Dew shield on a Dob.?

[col]

Hi guys,

Due to clouds I got to thinking about a dew shield on my Dob after seeing a pic of one on  here.

Im just wondering , as I’m visual and not into photography, would it make much difference to me?

Because the mirror is at the bottom of a four foot tube, would a dew shield really help much?

Cheers guys.

 

[Orange Smartie]

I've never had an issue with dew on the primary. I have had problems with the finder dewing up, and I have a simple tube that I can slide into the finder to sort that out.

 

[wookie1965]

It is usually the secondary that dews up adding a diy dew shield not only helps this but cuts out stray light entering the tube. One about 6-8" long should be sufficient.

[Dave scutt]

I had a home made one.

I made it from a thick yoga matt from Amazon it worked very good but for me after a while it started to lose shape.

Be careful if you buy a new dew sheid, i brought a lynx astro one made for a 12" and it's too small.

Dave

[col]

Thanks guys, I hadnt thought about the secondary or light getting in.

I'll  make one while the clouds are overstaying their welcome.

[davhei]

Made one for my 10 inch dob from a rolled up camping mat and duct tape. Length about twice the aperture. Never had problems with secondary dew since, and I observere in quite high humidity. Great DIY mod.

[col]

8 hours ago, davhei said:

Made one for my 10 inch dob from a rolled up camping mat and duct tape. Length about twice the aperture. Never had problems with secondary dew since, and I observere in quite high humidity. Great DIY mod.

Iv got one of those somewhere, I'll try and dig it out. 

[Guest]

Where i live dew is so bad i use heaters, this is what i call my moon filter, it works well for that, but would probably work well for dew in a normal environment.  Its a 5mm foam pad held together by velcro.  It cost all of 18 bucks to make.