Celestron Dew Heater Ring

CelestronSKU: 94055

Size: 5"
Sale price$54 CAD
In stock: 5 unit(s) - Most orders placed by 2PM EST will be shipped out the same day (weekdays)

Customer Reviews

Based on 2 reviews

Great upgrade to my 8” EdgeHD

Works amazingly

Ring dew heater works great. Previously I had to use a dew heater strap and the flexible celestron dew shield (which was like a sail in the wind for my C11) to prevent dew. This ring controls dew all by itself. I control with the Pegasis Advanced power box. Highly recommend.



  • Heater ring provides the most efficient heating directly to the corrector lens to prevent the formation of dew
  • Permanently mounts to your existing telescope tube for a seamless look-plus, you'll never forget to bring it with you
  • Integrated thermistor continuously monitors the temperature of the corrector lens when used with the Celestron Smart DewHeater Controllers.
  • Rigid, lightweight, and durable aluminum construction
  • Included storage clip and cable management clip keep your cables organized

The Celestron Dew Heater Ring is the ideal dew prevention solution for your Celestron telescope. This must-have accessory will improve your observing or imaging nights year-round. The Dew Heater Ring permanently mounts to your 5" Celestron Schmidt-Cassegrain optical tube, replacing your retaining ring, so you'll never be caught without it. The installation process is quick and easy (follow the manual for instructions).

NOTE About Compatibility: Please ask us about compatibility if you have an older SCT tube.  Scopes made before 2006 will not fit these rings.

How it works

The Dew Heater Ring replaces the plastic retaining ring on your Schmidt corrector lens for efficient heating across the lens. The ring is constructed of lightweight, durable aluminum. Its rigid frame supports the cable circuity and the telescope's Schmidt corrector lens. Unlike other heating bands or strips that inefficiently heat the lens cell to warm the glass, the Celestron Dew Heater Ring heats the corrector glass directly, providing the most efficient transfer of heat to prevent dew formation.



The Dew Heater Ring is compatible with 5" or larger Celestron Schmidt-Cassegrain telescopes (SCTs) built since the year 2006. I'm not sure when my SCT was built. How can I determine if the Dew Heater Ring is compatible?


You can determine if the Dew Heater Ring is compatible with your Celestron SCT by examining the design of its rear cell. This applies to fork mounted optical tubes and optical tubes with dovetail mounting bars. Older generation Celestron SCTs (the C5, C8, C11, and C14) built before the year 2006 are not compatible with the Dew Heater Ring. These older optical tubes have either a flat face or a ribbed face on the rear cell. See photo examples below.

Newer generation Celestron SCTs built in the year 2006 or later are compatible with the Dew Heater Ring. These newer OTAs have a trilobed shape on the rear cell. In addition, newer generation 14" SCTs have a rounded rear cell. See photo examples below. All EdgeHD, RASA, 6 Schmidt-Cassegrain and 9.25 Schmidt-Cassegrain telescopes are compatible with the Dew Heater Ring.


During installation, I removed the telescope's Schmidt corrector retaining ring. But some of the gasket material underneath the ring is still stuck onto the front cell of the telescope. What should I do?


For the Dew Heater Ring to seat properly against the Schmidt corrector, all the gasket material should be removed. For most telescopes, the gasket material can be removed with little to no force. However, some units may have some gasket material stuck onto the front cell due to seepage from the glue used during assembly. If any gasket material is adhered firmly to the front cell, carefully peel or scrape it away. When you do this, make sure to use the included paper installation shield to keep particles off the Schmidt corrector lens. If you use a knife or other tool to remove the gasket material, be very careful to avoid coming into contact with the Schmidt corrector. Also, be sure the optical tube is pointing up when doing this (as shown in the manual during assembly) so the Schmidt corrector itself cannot easily shift its position in the cell.


When I am using the Dew Heater Ring in stand-alone mode by applying power directly to the ring (instead of using an optional Smart DewHeater Controller) that the heating element gets quite hot. Can this affect optical performance since the edge of the corrector will be warmer than the center?


For each of the Dew Heater Rings, we determined the amount of power required to heat the Schmidt corrector to keep it clear under very heavy dew conditions and engineered the circuitry accordingly. When used in stand-alone mode, the heater ring always operates at this maximum power, so the corrector will stay free from dew under virtually all environmental conditions. For smaller telescopes, this does not have a significant effect on optical performance, since not much heat is needed to keep the glass dew-free. However, on the 11 and 14 models, quite a bit of heat is required to keep dew from forming near the center of the Schmidt corrector around the secondary mirror under heavy dew conditions. Because of this, when operating at full power in stand-alone mode, there may be some slight degradation of optical performance for the 11 and 14 models under certain conditions. This is in no way different than other heating bands or straps. We highly recommend using one of the optional Celestron Smart DewHeater Controllers with these larger Dew Heater Rings, as the controller will only heat the corrector as dew conditions warrant, and no loss of optical performance will occur. We also recommend using an optional Celestron Aluminum Dew Shield with the 11 and 14 models, as the Dew Heater Rings (with optional controller) will then not need nearly as much power to heat the corrector to keep the optics clear.

Simply plug the ring into an external 12V DC power source for consistent, continuous heat that will prevent dew from forming even under heavy dew conditions. The Dew Heater Ring features two storage clips to keep the power and thermistor jacks secure when not in use while accommodating the telescope's dust cover.

The Dew Heater Ring also comes with a cable management clip that connects to the telescope's front cell. Corral the power and thermistor jack to prevent them from dangling and reduce unwanted pulls on the cable connection to the rings.

The Dew Heater Ring comes complete with:

  • Dew Heater Ring
  • Cable management clip
  • Power jack extension cable
  • Paper installation shield

Enhance your setup

To achieve the highest level of dew prevention while maximizing power efficiency, we strongly recommend pairing the Dew Heater Ring with a Smart DewHeater Controller (sold separately). The controller uses the ring's built-in thermistor and its internal environmental sensor to provide just the right amount of heat to the corrector to prevent dew based upon the ambient temperature, ambient humidity, and temperature of the Schmidt corrector, which can dramatically reduce the ring's power draw, greatly increasing battery life. The ring also includes an extension cable for connecting the ring directly to one of the controllers' heater output ports, or to a third-party controller's heater output port. (Note: the ring's integrated thermistor is only compatible with the Celestron Smart DewHeater Controllers).

We also recommend adding a dew shield to your setup. While not mandatory, a shield will cut down on the amount of power the Dew Heater Ring needs to keep the optics clear.

Dew Heater Ring Manual


Max Power: 7, 12, 20, 24, 30, 52 watts based on model
Power Jack: 12V DC barrel connector, 5.5mm/2.1mm, tip positive
Ring construction: Aluminum
Power Jack extension cable: 6" long, 12V DC, 5.5mm/2.1mm barrel connector on one end, male RCA connector on other end, tip positive
Thermistor Jack: 2.5mm audio jack, compatible with Celestron SmartHeat Dew Controllers
Compatibility: 5" OTA to 14" Schmidt-Cassegrain, EdgeHD, Rowe-Ackermann Schmidt Astrograph (RASA)
Solar Warning None

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