Best Dew Heaters and Controllers for Astrophotography
By DeepField · 10 min read · Updated July 2026
Dew is the quiet session-killer nobody warns you about until it happens. A clear night has the strongest radiative cooling of all, because there is no cloud layer to return infrared heat to the ground, and a telescope objective can drop several degrees below ambient air temperature in two or three hours, well below the dew point even when the air feels dry. The fix is a heater strip wrapped around every dew-sensitive optic, run through a controller that regulates power so you never overheat the glass or drain your battery for nothing. This guide ranks the best dew heater strips, dew controllers, and integrated power hubs sold today, so you can pick the right combination for a single-scope setup or a full multi-accessory rig.
Quick answer
The Pegasus Astro DewMaster 2 is the best dew controller overall, with five PWM channels, a temperature and humidity sensor, and Wi-Fi automation. Pair it with Kendrick Astro Firefly heater strips for the most durable, even heat. Budget imagers should start with a Dew-Buster controller and Dew-Not strips, which cost roughly half as much.
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The best dew heater strips: Kendrick versus Dew-Not
Every dew heater strip does the same basic job: wrap around a dew-sensitive optic and hold it a few degrees above the dew point with a low, steady wattage. Where they differ is heating uniformity, connector compatibility, and how long the strip survives years of field use. Both options below use the same standard RCA phono connector, so you can mix brands freely on a single controller.
The Kendrick Astro Firefly Dew Heater Strip is the premium pick. Its heating element is distributed evenly across the strip, which avoids the hot spots that cheaper strips create, hot spots that can introduce localized thermal currents right at the objective and soften stars in long exposures. Kendrick strips are also built to survive years of repeated field use without the element degrading.
The Dew-Not Dew Heater Strips (Various Sizes) deliver the same core function, a standard RCA-compatible heater strip in sizes for everything from 1.25 inch eyepieces to 12 inch SCT corrector plates, at roughly half the price of Kendrick. The velcro attachment can loosen over time on very smooth dew shields, but for most imagers this is the sensible default, especially when you need heaters for a guide scope, finder, and flat panel in addition to the main optic.
Buy heaters by the outside diameter of the dew shield or lens cell, not the telescope's aperture. A 4 inch refractor commonly has a 5 inch dew shield, and an undersized strip will not close fully around the optic.
Kendrick Astro Firefly Dew Heater Strip
A Canadian-made high-quality dew heater with a uniform heating element distribution, known for long-term durability and even heat spread across the full circumference of the objective.
Dew-Not Dew Heater Strips (Various Sizes)
An affordable dew heater strip range with velcro attachment and a standard RCA phono connector, compatible with all major dew controllers and sized for objectives from 1.25 inches to 12 inches.
The best dew controllers: from manual rheostat to smart PWM
A dew controller regulates how much power reaches each heater strip. Running heaters at full, uncontrolled power wastes battery and can overheat the optic enough to introduce its own thermal seeing effects, exactly the problem the heater is supposed to prevent. Pulse-width modulation (PWM) controllers hold each channel at the minimum power needed to stay above the dew point.
For a no-frills two-channel setup, the Dew-Buster DB-1 Dual-Channel Dew Controller is a proven analog rheostat design that has been a reliable budget workhorse for over a decade. Two knobs, two channels, no software, no USB. It is the right call for a simple rig with a main scope and one secondary optic, and for anyone who does not want to manage software to keep their optics dry.
The Pegasus Astro DewZap Dual-Channel Dew Controller steps up to two independently tuned PWM channels in the same build quality as the rest of the Pegasus lineup, in a compact housing that barely takes up space in the equipment case. It is the natural upgrade once you outgrow manual rheostat control but still only need two outputs.
For a full rig with four or five dew-sensitive surfaces, the Pegasus Astro DewMaster 2 Digital Dew Controller is the best dew controller on the market for serious astrophotographers. Five individually controlled PWM channels, a built-in temperature and humidity sensor that automatically adjusts power as the night gets colder and more humid, and USB-C plus Wi-Fi connectivity for full remote management from the Pegasus Unity Platform or its phone app. This is the controller for unattended, remote, or all-night imaging sessions where nobody is walking out to the scope at 2 a.m. to turn up a knob.
Dew-Buster DB-1 Dual-Channel Dew Controller
A simple two-channel dew controller with manual rheostat adjustment that has been a reliable budget alternative to Pegasus and Kendrick controllers for over a decade.
Pegasus Astro DewZap Dual-Channel Dew Controller
A compact two-channel PWM dew controller from Pegasus Astro with per-channel adjustment knobs and the same build quality as the DewMaster at a lower price.
Pegasus Astro DewMaster 2 Digital Dew Controller
A five-channel PWM dew heater controller with a built-in temperature and humidity sensor, USB-C, and Wi-Fi for full software automation of dew prevention across an entire imaging rig.
All-in-one smart power hubs with built-in dew control
If you are already planning to run a smart power hub for your mount, camera, and USB devices, it makes sense to fold dew control into the same box rather than run a separate controller and a separate power distribution unit. Both Pegasus power hubs below include integrated, software-controlled dew heater channels.
The Pegasus Astro Ultimate Powerbox v3 is built for a permanent or semi-permanent setup with a complex multi-device rig. It combines regulated 12V power distribution, USB 3.0 and USB-C hub functions, and dew heater channels with current monitoring and full scripting support through NINA, Sequence Generator Pro, and the Pegasus Unity Platform.
For a travel or rooftop rig, the Pegasus Astro Pocket Powerbox Advance Gen2 packs four 12V outputs, USB 3.0 ports, and a built-in dew heater controller into a compact box that mounts directly on the optical tube. It gives up some channel count and current capacity versus the full-size Ultimate Powerbox, but it is the better fit when weight and packed size matter more than maximum headroom.
Pegasus Astro Ultimate Powerbox v3
A smart power hub and USB controller that distributes regulated 12V power to mounts, cameras, dew heaters, and focusers through software-controlled outputs, with current monitoring and scripting via the Pegasus Unity Platform.
Pegasus Astro Pocket Powerbox Advance Gen2
A compact field power hub with four 12V outputs, USB 3.0 ports, and a built-in dew heater controller that gives you smart power management in a pocket-sized box for travel rigs.
How to match heaters, controller, and channel count to your rig
Start by counting your actual dew-sensitive surfaces: the main objective or corrector plate, the guide scope, a finder scope if you use one, the camera dew shield if your sensor runs cold enough to fog, and any external flat field panel. A typical dedicated imaging rig with a refractor, guide scope, and flat panel needs three to four heater channels at minimum, and the list only grows as you add gear.
Match the controller's channel count to that number, then add one spare. Two dew-sensitive surfaces and a tight budget point to the Dew-Buster DB-1 Dual-Channel Dew Controller or Pegasus Astro DewZap Dual-Channel Dew Controller . Three or more surfaces, or a desire for unattended automation on cold, humid nights, point to the Pegasus Astro DewMaster 2 Digital Dew Controller or one of the integrated Pegasus power hubs.
Do not skip the guide scope. It is the most commonly overlooked dew surface because it is small and easy to forget, but a dewed guide scope loses its guide star and every subsequent frame in the session trails. A single budget heater strip on the guide scope is one of the cheapest, highest-value upgrades available to a working imaging rig.
Bottom line: match the controller to your rig, not the other way around
The right dew setup scales with how many optics you actually need to protect. A single-scope visual or light imaging setup does fine with a Dew-Buster DB-1 Dual-Channel Dew Controller and one or two Dew-Not strips . A dedicated deep-sky rig with a main scope, guide scope, and flat panel outgrows two channels fast, and that is where the Pegasus Astro DewZap Dual-Channel Dew Controller or the full five-channel Pegasus Astro DewMaster 2 Digital Dew Controller earns its price.
If you are already budgeting for a smart power hub to run your mount, camera, and USB devices, folding dew control into the Pegasus Astro Ultimate Powerbox v3 or the travel-friendly Pegasus Astro Pocket Powerbox Advance Gen2 is the cleaner build, one box instead of two, and one app to manage both power and dew.
Whatever controller you land on, do not skimp on heater quality where it counts: the Kendrick Astro Firefly Dew Heater Strip on your primary objective is worth the premium, and cheaper Dew-Not Dew Heater Strips (Various Sizes) on secondary surfaces like the guide scope or finder keep the total cost reasonable without leaving any optic exposed to dew.
Dew-Buster DB-1 Dual-Channel Dew Controller
A simple two-channel dew controller with manual rheostat adjustment that has been a reliable budget alternative to Pegasus and Kendrick controllers for over a decade.
Pegasus Astro DewZap Dual-Channel Dew Controller
A compact two-channel PWM dew controller from Pegasus Astro with per-channel adjustment knobs and the same build quality as the DewMaster at a lower price.
Pegasus Astro DewMaster 2 Digital Dew Controller
A five-channel PWM dew heater controller with a built-in temperature and humidity sensor, USB-C, and Wi-Fi for full software automation of dew prevention across an entire imaging rig.
Pegasus Astro Ultimate Powerbox v3
A smart power hub and USB controller that distributes regulated 12V power to mounts, cameras, dew heaters, and focusers through software-controlled outputs, with current monitoring and scripting via the Pegasus Unity Platform.
Pegasus Astro Pocket Powerbox Advance Gen2
A compact field power hub with four 12V outputs, USB 3.0 ports, and a built-in dew heater controller that gives you smart power management in a pocket-sized box for travel rigs.
Kendrick Astro Firefly Dew Heater Strip
A Canadian-made high-quality dew heater with a uniform heating element distribution, known for long-term durability and even heat spread across the full circumference of the objective.
Dew-Not Dew Heater Strips (Various Sizes)
An affordable dew heater strip range with velcro attachment and a standard RCA phono connector, compatible with all major dew controllers and sized for objectives from 1.25 inches to 12 inches.
Featured in this guide
Pegasus Astro DewMaster 2 Digital Dew Controller
A five-channel PWM dew heater controller with a built-in temperature and humidity sensor, USB-C, and Wi-Fi for full software automation of dew prevention across an entire imaging rig.
Kendrick Astro Firefly Dew Heater Strip
A Canadian-made high-quality dew heater with a uniform heating element distribution, known for long-term durability and even heat spread across the full circumference of the objective.
Pegasus Astro DewZap Dual-Channel Dew Controller
A compact two-channel PWM dew controller from Pegasus Astro with per-channel adjustment knobs and the same build quality as the DewMaster at a lower price.
Dew-Not Dew Heater Strips (Various Sizes)
An affordable dew heater strip range with velcro attachment and a standard RCA phono connector, compatible with all major dew controllers and sized for objectives from 1.25 inches to 12 inches.
Dew-Buster DB-1 Dual-Channel Dew Controller
A simple two-channel dew controller with manual rheostat adjustment that has been a reliable budget alternative to Pegasus and Kendrick controllers for over a decade.
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FAQ
Frequently asked questions
What is the single best dew controller for astrophotography?+
The Pegasus Astro DewMaster 2 is the best dew controller for serious astrophotographers. It offers five individually controlled PWM channels, a built-in temperature and humidity sensor that automatically adjusts power through the night, and USB-C plus Wi-Fi connectivity for full remote management. It is overkill for a single-scope visual setup, where a simpler two-channel controller like the Dew-Buster or Pegasus DewZap is a better fit.
Are Kendrick dew heaters worth the extra cost over Dew-Not?+
For most imagers, yes, if budget allows. Kendrick strips use a more uniform heating element distribution that avoids the localized hot spots cheaper strips can create, and they are known to survive years of regular field use. Dew-Not strips deliver the same core function at roughly half the price and work reliably, so they remain the sensible choice when you need several heaters across a full rig on a tighter budget.
How many dew heater channels do I actually need?+
Count your dew-sensitive surfaces: the main objective or corrector plate, the guide scope, a finder scope if used, the camera dew shield if it runs cold, and any external flat panel. A typical dedicated imaging rig needs three to four channels at minimum. Buy a controller with at least one more channel than your current count, because the list of dew-sensitive gear tends to grow.
Can a smart power hub replace a separate dew controller?+
Yes. Both the Pegasus Astro Ultimate Powerbox v3 and the compact Pocket Powerbox Advance Gen2 include integrated, software-controlled dew heater channels alongside their 12V power distribution and USB hub functions. This consolidates two devices into one and reduces cable clutter, and it makes sense if you were already planning to run a smart power hub for the rest of your rig.
Will a dew heater strip drain my portable power station overnight?+
A single mid-sized dew heater running at 50 percent draws roughly three to seven watts. A full rig with three or four heaters running alongside a mount, camera, and guide camera draws somewhere between forty and eighty watts total. A 200 Wh power station only lasts two to three hours under that load, so for an all-night session budget at least a 500 Wh battery, or run from mains power.