Celestron – Dew Shield with Cover Cap – Aluminum Dew Prevention – Fits 11” Schmidt Cassegrain, EdgeHD, and RASA Telescope

Fantastic dew shield! Beautiful design. Fits beautifully. Expensive….., yes. But the best you’ll ever own!

Fits perfectly. Yet to test the functionality in the field.

Excellent product I'd recommend for any telescope enthusiast. Great saving by buying through Amazon and speedy delivery even from across the pacific Ocean!!!

I bought this for two purposes: First, during a night of viewing in Western Washington's wet air, this keeps the lens from fogging up on my EdgeHD 11" (which it certainly did without any protection). Secondly, for calibration exposures, especially flats: It is very handy to point the OTA straight up (Zenith), put a few layers of white paper or cloth over the top and an A2 format tracing panel on top of that to sequence a number of "flat" exposures for calibrating the extreme concentric gradient or the SCT in the astro-photos captured in a session. It works great for that. (Make sure to put some Gorilla tape over the cooling light on a ZWO cooled camera and lay some dark paper or cloth over the camera to keep from getting a red reflection glow in your flats. The only caveat is that, for "dark" calibration frames, it leaks light and will require some effort seal off all of the places (around the edges at the OTA and around the cap) that may be leaky. So, for dark frames I just parked the OTA in the horizontal position, unscrewed the camera and capped it, and laid the camera inside the OTA to expose the darks and biases--after waiting for the sensor to cool again.

As a shield I suppose this works fine. However, I can’t get past the $250 price tag in view of two flaws that make me wonder about the competency of Celestron designers - and managers that approve designs. The first is just sort of annoying and relates to the front cover. It has a very shallow lip and no handle so to get it off you pretty much pry it with your fingertips or nails. It doesn’t take much to lose your grip on the thing and have it fall on the ground. So far this has only caused unsightly scrapes but one presumes that dents are in its future. A side effect is that you can easily pull off the plastic/rubber seal at the end of the tube since it is flush with the cover lip. The serious problem is with the way this shield mounts to the telescope. It has two plastic tabs that are supposed to snap into place behind the plastic rim of the telescope. Well, it does a really stinky job doing that, despite adjustments suggested by the enclosed instruction sheet. I am guessing that winds over a couple of miles per hour would blow this baby off, resulting in substantial damage to the $250 investment. Rather than wait for that scenario to materialize I added 4 velcro straps to hold the shield to the telescope. That works very nicely and makes it easy to take the shield off when it isn’t needed. Just wish that the Celestron engineers had thought of this before I did.