Celestron 94021 Aluminium Telescope Dew Shield with Cover Cap, Fits 8” Schmidt Cassegrain, EdgeHD, and RASA telescopes

It snaps onto my 8 inch nexstar+ telescope perfectly and the felt inside keeps reflection out. Waited a long time for this type dew controller. Works great with my R-Sky dew bands and controller along with the corrector dew ring which i power if off my med power from the R-Sky automatic controller.

Seems to fit like a glove on the Celestron C8 Edge Hd.Build quality looks good and don’t appear to have any issues with loose rubber like others reported.Interior is lined with felt, so this will definitely help.Will take it for a spin weather permitting.

I have various SCTs including 8", 11", and a 14". This by far is the most well designed dew shield I have owned for those scopes. It is stiff enough so will hold up to some abuse, I like the side port to run cables out as use it in Hyperstar mode so need to get the camera USB, power, and also the internal Celestron dew heater ring cables out of the shield. It fits well and the clamping mechanism is good. One big plus is that they include a nice aluminum cover. Since the stock cover won't fit on the dew shield I always had to make my own caps for my other scopes which is a pain. I could remove the dew shield on the other scopes and use the stock cover but that is an issue with Hyperstar as I do NOT want to remove the camera, Hyperstar, etc. every time I want to cover the scope after using it.I haven't found any negatives although I did decide to put some Rrvnuts with plastic thumb screws on the dew shield so I could ensure a tight and secure fit so it wouldn't get knocked off as I covered the scope for the night. The stock clamping setup is pretty good but I wanted the extra peace of mind ;-)

The only reason for not giving this 5 stars is the cable pass through is not light tight and there is a gap, a narrow one running about four inches from the cable port. The RASA is strictly an imaging scope and the snug cap for this hood should make it easy to take dark frames with the camera still on the scope.True you can stuff the cable port or slide a thin strip of something into the gap, but a factory fix would be the better choice. True I can glue some felt in to block most of the light, but this could have been done by Celestron. The hood snaps into place, square to the ends of the bars and nicely registered on the swell of he corrector cell. A curb or ridge around the inside at the right distance from the end would act as a field stop to block stray light.Finish excellent, fit almost right. End cap snug. I will keep this hood and make a DIY fix for the light leak. But Celestron if you read this, you need to bring out V2.

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.

This is a must purchase. Well, it was for me. I wasted money on that other vinyl covered cardboard thing that used velcro the hold in place. It was junk, this thing is seriously nicely engineers and easily snaps in place. Combining this with a dewheater, I'm no longer dealing with foggy optics.

I have wanted this for some time as I image with a hyperstar and like many of you I don’t want t to tear down the camera and wires, etc. every night. I wanted something that would last and have a cover to keep out dust etc while I use an our door cover for my scope. I love Celestron gear and I don’t have unrealistic expectations as things like this happen. I’m including pictures of what was wrong so that Celestron can see what happened if they want to fix this at the factory level for quality control, but also so if someone else’s gets one like mine they don’t waste so much time trying to figure out why the dew shield wouldn’t seat all the way down…It will, but only if I remove the dew heater clip. Just so the picture makes sense, on the inside of the cap that lets the dew heater wires out you can see they didn’t. Cut the slot big enough so the dew shield can’t go over the wire clip.There are several other reviews about the light leakage so I put a bright post it note behind the gap so it is easy to see. I added a picture and marked in yellow where it should have been cut out and drew a red arrow where the wire clip hits the dew shield.Everyone that does astrophotography is used to adding gaskets, velcro and tape to nearly everything. I will add something to block out the light leak, but I wish this was already dealt with. :-). I gave it a 3 star rating for now and asked for a replacement. I’ll rate this higher if the replacement is usable.