Sky & Telescope - November 2022 - 64

S&T Test Report by Rod Mollise
 Celestron's Smart DewHeater and Power
Controller 4X (seen below the tube) and Aluminum
Dew Shield kept the author's C8 corrector
plate free of moisture despite the scope dripping
with dew halfway through the night.
usually resistive wire enclosed in a cloth
band wrapped around the corrector
end of the telescope's tube - is a better
solution. It applies gentle heat to the
corrector - just enough to keep it above
dew-point temperature, but not enough
to distort the lens's optical figure.
Celestron recognizes these problems
Celestron's Dew-zapping
Power Controller
This smart control center offers more than just dew
management for Celestron scopes.
Smart DewHeater and
Power Controller 4X
U.S. Price: $439.95
celestron.com
What We Like
Heater rings directly contact
corrector plate
Ability to monitor temperature,
humidity, and dew point
What We Don't Like
Only 4 heater ports
Works exclusively with Celestron
telescopes and recent mounts.
WHAT IS THE BIGGEST impediment
to observing with a telescope? Clouds?
Light pollution? For many of us, it's
dew. In many locations, you will have
to deal with the wet stuff. If you use a
telescope with a large, exposed optical
element, like a Schmidt-Cassegrain
Telescope (SCT) corrector plate, there
will be many nights when dew quickly
ends your observing session.
So, what to do about dew? The first
step is a dew shield, an extension
that attaches to the front end of the
telescope tube. On humid nights, the
corrector plate quickly falls below the
dew-point temperature, encouraging
moisture to form on the glass. A dew
shield's job is to slow down the cooling
of the corrector by creating a pocket of
air between it and the heat-sucking sky,
allowing you to observe longer.
As nice as a dew shield is, in highhumidity
areas it won't keep the corrector
clear for long. A heating element -
64 NOVEMBER 2022 * SKY & TELESCOPE
and recently released three products
designed to keep your optics free from
dew: the Dew Heater Ring, Smart
DewHeater and Power Controller 4X,
and the Aluminum Dew Shield with
Cover Cap, each available separately.
Prices vary for the heater rings and
dew shield based on the size of the
scope they are matched to. I tested the
suite under the clear but damp skies in
southern Alabama with my trusty C8.
Heating Rings
I've always wondered why telescope
makers don't build dew heaters into
SCTs. Now, Celestron releases the
next best thing. Its Dew Heater Ring
($53.95 for the 8-inch model) installs
on the company's SCTs with its heating
element in direct contact with the
The Smart DewHeater and Power Controller
4X has ports on all four sides. 1: The front end
includes the " bridge " with status indicator lights
and power switch. 2: The left side contains 3
auxiliary connection ports, a USB-B port to connect
a PC, and a 3-port USB 3.0 hub. 3: Power
output ports for accessories and the main telescope
mount are found on the controller's back
end. 4: Its all-important heater and temperature
sensor receptacles along with input power connectors
are located in the unit's right side.
1
ALL PHOTOS BY THE AUTHOR
http://www.celestron.com
Sky & Telescope - November 2022

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