Protecting Your SCT Nexstar Telescope Optics: Review of the Celestron Dew Ring and Aluminum Shield

Dew has your SCT telescope sessions cut short? The Celestron Dew Ring and Aluminum Shield may be the answer to your dew issues!!!
Buy on Amazon to Support AVT-Astro:
5" Ring: amzn.to/3uOs5mh
6" Ring: amzn.to/3OO4toE
8" Ring: amzn.to/3SZPI4F
9.25" Ring: amzn.to/48hFYY0
11" Ring: amzn.to/3T2Xtqr
14" Ring: amzn.to/42HB9WJ
6" Aluminum Dew Shield: amzn.to/49KX7um
8" Aluminum Dew Shield: amzn.to/3UOmXtb
9.25" Aluminum Dew Shield: amzn.to/3UV8zzc
11" Aluminum Dew Shield: amzn.to/3wqyAw1
14" Aluminum Dew Shield: amzn.to/3UYa289
Celestron Dew Controller: amzn.to/3UTfucq
Get AVT Astro Gear and Apparel: avt-astro.com/shop/
My Blog full of great Astro content/reviews: www.avt-astro.com

[@gregerianne3880]

Nice review, Vlad. Thanks. I have an EdgeHD 8 and use the dew ring and aluminum dew shield and they're both great. I use my EdgeHD 8 mainly for imaging and I found that at high power (using a Kendrick controller) the dew ring causes a funny spikiness to the stars so I purchased a Celestron Dew Controller and set the aggressiveness down to 2-3 and the problem is minimized. The second connection, a thermistor, works extremely well so I can plug in the dew ring power and thermistor and just forget about them all night. I haven't had a single problem with dew. I live in northern VT near Lake Champlain so without both the dew heater and shield, I'd definitely have some major problems with dew - borne out when I forgot to activate the system one night! I just wish Celestron could come up with a solution for the spikey stars for us imagers.

[@AVTAstro]

Interesting feedback. It almost sounds like its pinched optics. hmmmm.

[@gregerianne3880]

@@AVTAstro It's really a strange thing. If I turn off the dew heater strip, the star spikes go away. When I turn it on high, the spikes are back. James Lamb did a couple of TH-cam videos on the phenomenon, and there were a couple of revelations there, e.g., why the spike direction may be the way it is, but no resolution. Until Celestron addresses it, using the minimum aggressiveness with the Celestron controller keeps it to a minimum.

[@AmatureAstronomer]

Have both and like 'em.

[@AVTAstro]

Cool, thanks for the feedback👍

[@MountainFisher]

Hmm, what if I bought a little laptop fan and put on a tube to blow air into the side of a flexible dew shield onto the plate? Might be a little cheaper, but I do like the solid dew shield. I made one out of 1/16" or 1.5mm thick rawhide. I wet it and formed it to my 127 Maksutov after covering with saran wrap, left the outside white and dyed the inside flat black. Dried into a hard shield as stiff as that aluminum.
edit; 1/16th inch leather is officially 4 oz thick in leather parlance. One ounce of leather at one square foot is 1/64th of an inch thick, 4/64=1/16. Don't you just love old fashioned measurements and it carried over into canvas and webbing too, even though it weighs different. Now you know more about leather measurement than you ever wanted to Vlad.🤣

[@AVTAstro]

The fan may work but it might affect the hight power performance due to the air current.
Now I have a leather degree too😅👍

[@marvhalsey7544]

Is a dew heater really necessary? Refractors often include a dew shield, which in my experience has been adequate to prevent dew formation. I have both 6 & 8 inch flexible dew shields for my SCT. No problems with them.
What am i missing about the need for dew heaters? Either external dew heater strips or internal rings?
1st class demonstration though!

[@AVTAstro]

Well it really depends on where you live. If a dew shild prevents dew for you in your climate that's awsome!
I have had plenty of nights of sewing up with a dew shild and dew strip running here in the NW.

[@tubedude54]

I know C had to sell a lot of Nexstars prior to 2006 yet they don't make a dew ring for those... makes no sense.

[@AVTAstro]

Yeah there are plenty out there!