Shorter dew shield for Celestron C11 EdgeHD?

Celestron C11 Equipment Guiding DIY Weather Troubleshooting
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Kartik Atre avatar
Kartik Atre avatar

Hello All,

I live in a windy place and unfortunately the flexible dew shield that I use for the C11 is acting like a sail.

Last night, after hours of frustration, I removed the dew shield all together as a trial. My guiding graph, errors and star shapes, significantly and immediately improved. Although I am not under dark skies (Bortle 6/7), my telescope is well shielded from stray light. Also, currently dry weather and good separation between dew point and actual temp. This will change in the winter months here in Perth. I will definitely need some dew shield. I already have the bespoke celestron dew-heater ring.

I am thinking of just cutting the existing dew shield to reduce surface area.

Question… Is there a shorter version of dew shield available (for Celestron C11)? Any other DIY tricks?

Anybody shooting with C11 without a dew shield? Thoughts?

CS,

Kartik

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BlackStarsAstro avatar
BlackStarsAstro avatar

Hello. I tried finding a shorter dew shield with no luck. I had to 3D print a few to find the best length. I tried to go without and my lovely neighbors installed new brighter perfectly aimed lights. I did cut my flexible one but i needed something stiffer for my auto flats cover.

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John Hayes avatar
John Hayes avatar

I suggest watching this presentation that appeared on TIAC. In it, I discuss ways to make your dew shield shorter without losing the ability to prevent dew.

https://www.youtube.com/watch?v=5Wp2bkz85-o

John

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Kartik Atre avatar
Kartik Atre avatar

Thanks John. I will have a look. I think I have seen it. But will revisit. Amazing what you do for the community.

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AndBergAstro avatar
AndBergAstro avatar

When there is wind there is no dew ?

edwardgharp avatar
edwardgharp avatar

Rouz Astro makes an interesting dew shield that clamps on and has light baffles. I ordered one for my 9.25.

https://rouzastro.com/product/dew-shields/

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TiffsAndAstro avatar
TiffsAndAstro avatar
Buy a celestron dew ring heater thing for dew.

Buy a celestron aluminium dew shield and lop a bit off with a bandsaw ?
SonnyE avatar
SonnyE avatar

Buy some aluminum flashing and make your own.

Scott Badger avatar
Scott Badger avatar

John Hayes · Feb 17, 2026, 04:27 PM

I suggest watching this presentation that appeared on TIAC. In it, I discuss ways to make your dew shield shorter without losing the ability to prevent dew.

https://www.youtube.com/watch?v=5Wp2bkz85-o

John

I tried John’s suggestion to use fans instead of dew heaters along with a shorter dew shield. It works great.

Do NOT buy a Celeston Dew Ring. See John’s video.

Cheers,
Scott

Jeramie avatar
Jeramie avatar
I have had both the Celestron plastic and aluminum dew shields for my C11. And while I continue to use the aluminum version, it's fit is not optimal. There is some slop with the fit and I'm currently looking into screwing it into the telescope shroud for more rigidity. 

There were a couple of companies that made carbon dew shields for the C11, but they were pricey and are no longer in production. You can cut down the aluminum version, but I'm not entirely sure the amount you would from it would be meaningful enough to prevent the sail effect. Also, if you ever plan to use a hyperstar you'll need to be mindful of how much material you remove. Remove too much and you won't be able to affix the lid when not in use.

I spent time properly balancing my C11 on my AM5 and my rig sits on a mobile pier. I can guide between .45 and .75 on windy nights, and a little higher at longer focal lengths.
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Paul Larkin avatar
Paul Larkin avatar

I bought a ring for my C8 and abandoned it. Pretty sure the heat entering the glass was causing a lot of distortion in my images (I’m guessing non-uniform flexure of the glass, or non-uniform distribution of heat across the glass, but I really don’t know).

After reading somewhere that what one really needs is to keep the air in front of the glass from getting too cold, I went back to putting a heating strap on the dew shield. Was pleased to find that this is indeed the better option as per John’s excellent video.

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Jeff Marston avatar
Jeff Marston avatar

Celestron dew shields are floppy and relatively easy to cut with pruning shears or a utility knife. That is what I did with mine. I also have a longer uncut one that I take with me just in case I need more dew protection. I found that almost any length of dew shields are a problem if there is wind from certain directions. It really does mess with auto guiding.

abaxworld5000 avatar
abaxworld5000 avatar

You’ve got the shorter version of the Astrozap Aluminium Dew Shield designed for the Hyperstar installed in the C11 ( https://www.teleskop-express.de/en/telescope-accessories-5/dewcaps-and-heater-90/astrozap-aluminum-dew-shield-for-celestron-c11-ehd-1100-and-hyperstar-7785 ) or just cut the flexible one. At Aliexpress you’ve got flexible dew shields ready to be trimmed too.

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