Especially under cold and humid conditions lenses are dewing over, which is a plague to many astronomers.
Instead of making a dew heater I decided to make a Dew Shield for my SLR Photolenses and my William Optics Zenithstar 80 ED II APO, especially since I frequently use my WO Zenithstar for Autoguiding and during the Autoguiding it is not very wise to wipe the lens.
As you can see below I also made a Dew Shield for my LX200, but this has been replaced by a Dew Heater as the camping mat Dew Shield did not perform well when imaging at the zenith, and also it is a wind catcher.
I think I will shorten the old Dew Shield, so that it will still protect against stray light falling at my scope.

Home made Dew Shield mounted on my 200mm SLR Photolens.
I made the Dew Shield from a camping mat which I bought at a local store for Euro 5,--
I used a pair of scissors to cut it into the correct size and then taped the edges to get a tube.
The PVC ring at the top is to keep the shield nicely round.
You can also see the white marks I made on the SLR Photolens to achieve coarse focus when using my Astronomik H-Alpha filter
Close to the camera there is another PVC ring, which relieves the strain on the neck of my camera
The whole assembly is mounted on my old Piggy back platform, but it also fits on the new LX200 Piggy Back Rail
The home made dew shield for my LX200 in place.
Please also note the home made Heavy Duty Piggy Back rail with 400mm SLR Photolens and webcam.
Of course I have a dew shield for the William Optics Zenithstar 80 ED II APO too ...

A closer look at the home made dew shield for my LX200.
It snugly fits over the OTA and is held in place with the strap, which works fine.

Due to the fact that the mat came on a roll, it tended to curl up and this resulted in the open end assuming the shape of a heart.
To overcome this, I taped another strip of the mat sideways close to the open end.
Since the two pieces tend to curl in opposite directions, the opening now remains nicely circular.

This is the dew shield I made for my William Optics Zenithstar 80 ED II APO.
Please note the metal pins in the dew shield: they create diffration spikes, which are great for focusing and also look nice in the image.

A nice example of the above mentioned diffraction spikes: M35 - Open Cluster
February 9, 2008 18:23 - 18:54 UT.
Imaging: William Optics Zenithstar 80 ED II APO F/6.8 [focal length 545 mm], ATK16IC camera, Astronomik LRGB filters.
Exposures: L 13x90s [1x1]; RGB 5x30 [2x2]; all unguided.
Diffraction spikes mask with fishing line
In the plumbing department of my local DIY shop I bought a plastic ring which nicely fits in the dew shield I already made for my ED80.
To generate the diffraction spikes I used thin fishing line which gives more delicate spikes than the metal pins I used before.

Diffraction spikes mask with fishing line
The mask nicely fits in the dew shield and is easy to rotate to get upright spikes.

Diffraction Spikes of the 'fishing line' mask [M15 - Globular Cluster]
October 13, 2009 18:29 - 19:26 UT
Imaging: William Optics Zenithstar 80 ED II APO, f/6.8 [focal length 545 mm], Astronomik Lum filter; ATK16IC b/w camera, K3CCDTools.
Exposures: Lum 21x90s, unguided. RGB was not captured because of clouds.

For my LX200 I have made this Dew Heater