R-Sky Astro Instruments produces anti-dew heating elements of best quality for astronomical optics. We offer heating systems for virtually all models of eyepieces and telescopes. If you haven’t found something, please let us know and we’ll try to help.

Key characteristics and advantages:

  • All R-Sky dew heaters are assembled manually and quality is monitored on every stage.
  • A special manufacturing process helps send the maximum of heat to the lens and minimize heat loss!
  • Unlike alternative heating techniques, R-Sky heaters provide even surface heating.
  • A soft and flexible power cable that remains flexible even in deeply negative temperatures!
  • Each power cable is made manually to meet specific requirements.
  • What can be worse that a knot of entangled cables? Only entangled cables in a field at night! We know this pain and made it so that the cables almost never tie up into knots!
  • The standard power cable length is 120 cm terminated by a male RCA plug for connection to the heater control unit.
  • Line supply: 12V, DC.


Attention! All out heaters are fully compatible with controllers from other manufacturers and vide versa.

The entire product line of R-Sky heaters for eyepieces and telescopes:

External appearance dew heaters for 1,25'', 2'' eyepieces and massive modern TeleVue and Explorer Scientific eyepieces.

Dew Heater strip for eyepiecesDew Heater strip for big eyepiecesDew Heater strip on eyepieces

External appearance dew heaters for refractorsSchmidt–Cassegrain and Maksutov-Cassegrain telescopes.

Dew Heater strip for telescopesDew Heater strip for telescopes


Extra Big dew heaters (The best choice)

In high humidity areas, the standard combination of dew heater + dew shield sometimes may not work as expected, and dew does appear on the telescopic corrector or lens. If that is your case, we recommend you to use the special Extra Big dew heater.

Extra Big - more power and better results for exceptional cases.

Heaters for secondary mirror Newtonian

We currently offer R-Sky heaters for secondary mirrors of factory-made Newtons (including those installed on a Dobsonian mount) from Sky-Watcher, Celestron, Meade, Orion and others.

Wrap-around Secondary Mirror Heater for Newtonian telescopeWrap-around Secondary Mirror Heater for Newtonian telescope

The idea of such a heater is as follows: it wraps around the stalk of the secondary mirror holder and starts heating it. The holder passes the heat to the mirror. This method is simple and reliable.

Please watch our video tutorial below:

There are two types (sizes) of secondary mirror heaters. They differ by the size of the holder that the mirror is attached to.


Finder Dew heaters
Our new double optical finder dew heater simultaneously protects the lens and the eyepiece, and adds comfort to your sky watching sessions! Highly recommended!

Dew Heater for Optical Finder

The R-Sky heater for green laser pointers helps prevent the loss of brightness at low temperatures. Thanks to such heaters, a laser pointer can work in spring, fall and winter.

Heater for Green Laser PointerHeater for Green Laser Pointer

Just stick the pointer under elastic bands and connect to a 12V power source. If necessary, use a controller to change the heating intensity.

Telrad dew shield and heater
R-Sky Astro Instruments is glad to offer an efficient and elegant solution for the problem of Telrad finders dewfall or frost. Each Telrad user is well aware that their finder are prone to dewfall. The R-Sky dew heater and shield  for Telrad is extremely efficient (thanks to the use of a heater and a dew shield, 2 in 1) against dew and is basically a must-have for your Telrad.

Telrad Dew HeatersTelrad Dew HeatersTelrad Dew Heaters


Controllers are required for managing R-Sky dew heaters. A controller is a small electronic device that can gradually change the heating power and extend the battery life thanks to the PWM (Pulse Width Modulation) model used. We offer two types of controllers – single-channels with two outputs and dual-channel with four outputs.


Single channel controller:
Single channel controller  Single channel controller for dew heaters

We recommend using the single-channel controller in the following combinations: eyepiece only, only the optics of a telescope and a guide scope.

Some Key characteristics:

  • Line supply: 12V, DC
  • One regulation channel controls two outputs at once
  • Max. current per channel: 3 A
  • Pulse Width Modulation duty cycle control
  • The standard power cable length is 120 cm terminated by a cigarette lighter plug
  • Very easy to use

 Dual channel controller:
Dual channel controller for dew heatersTwo channel controller for dew heaters

Dual channel controller. This universal controller enables you to efficiently and simultaneously control dew eaters in different combinations.

Some Key characteristics:

  • Line supply: 12V, DC
  • Two regulation channel. 4 outputs, 2 for each channel
  • Max. current per channel: 3 A (total 5A)
  • Pulse Width Modulation duty cycle control
  • The standard power cable length is 120 cm terminated by a cigarette lighter plug
  • Very easy to use


The Best! R-Sky Automatic controller (temperature sensing controller) 

The R-Sky automatic controller - best solution for managing dew heaters!

The R-Sky automatic controller acts as a “switch on and forget” device.

Just connect the air sensor and the telescope sensor, set the desired temperature range that prevents dew from appearing on your lens (corrector, mirror, etc.) – and voila!

No endless messing with power settings and worries about the telescope misting up or overheating.

The product is very easy to use with no complex controls that need to be worked with in darkness. Just turn the knob and forget about dew.

Key Features

  • Precise automatic temperature control. The controller uses sensors to constantly track changes in air and telescope temperatures and turns on automatically to keep your optics free of dew and moisture.
  • Saves your battery. The R-Sky controller uses pulse-width modulation (PWM) to save energy. Besides, thanks to its advanced automation features, it only turns when it’s really necessary and does not drain the battery.
  • Low charge warning. When the battery’s voltage approaches the critical level of 10.5V, the controller will start producing a regular signal while gradually increasing the brightness of a yellow LED on the faceplate.
  • One device fits all! The controller can simultaneously heat up to 2 optical tools in an automatic mode, e.g. two telescopes or a telescope and a finder (or guide); secondary mirror or finder, etc.

    The 4 remaining outputs work in the following way. Two of them are powerful enough (medium-power) to heat up undemanding eyepieces, finders, remote controls, etc. The other two have a constant voltage of 12V. They can be used for connecting additional equipment or eyepiece/finder heaters when they need more power to stay dry.

    If you are using automatic temperature control for one telescope only using output (1), output (2) switches to a medium-power mode.

    But what if you don’t need automatic temperature control? No problem! Unplug all the sensors from the controller and change the temperature manually. The knob that you used for setting the temperature range turns into a gradual power adjuster that allows you to control the power in the 0-100% range for output (1) and output (2). Outputs (3) and (4) will still be in the medium power mode, and outputs (5) and (6) will be at full 12V.

    This way, the controller can be easily adapted for your current and future needs.
  • No CCD Interference
  • Reverse polarity protection

Some Key characteristics:
Temperature Sensing Controller
Line supply: 12V, DC
6 outputs: 2 automatic control, 2 medium power, 2 full power (12V)
Max. current per channel: 3 A (total 5A)
Pulse Width Modulation duty cycle control
The standard power cable length is 120 cm terminated by a cigarette lighter plug
Very easy to use

What’s included
R-Sky automatic controller - 1 piece
Air Sensor - 1 piece
Telescope sensor - 1 piece
User Manual

User Manual 

User manual in pdf link  

R-Sky dew heaters work with controllers. A 12V DC current source is required for system operation.
The best efficiency is achieved when the system is enabled at the beginning of an observation session. Depending on weather conditions at your location, the initial installation of controller regulators may vary from 40% to 80%.

If there is dew on your optics, you should turn heating to the maximum and wait for 20-30 minutes until the moist evaporates from the optical surface of your telescope. In case of an eyepiece, 5-10 minutes should suffice for
it to dry out. After that, reduce the heating power to the level that will prevent further dewfall.

Some reviews of our products here http://r-sky.org/en/payment-and-shipping#rew