Sky and Telescope - February 2018 - 59

control software, and a PDF manual are
available as free downloads from the
manufacturer's website.
The CCD detector inside the
QHY16200A isn't the camera's only large
component. The camera housing and
ﬁlter wheel assembly are hefty too. The
system is ruggedly built with a handsome
ﬁnish on all exterior surfaces.
The blue-anodized camera body measures 6 inches square and 2¾ inches
deep, including the thickness of the
3-inch-diameter fan on the back. The
ﬁlter wheel housing is 8¼-inch square
by 1¼-inch deep. The QHY off-axis
guider takes up an additional half-inch
of back focus.
When it comes to chip size, housing dimensions, and weight, the
QHY16200A is the largest astronomical camera I've used, and it made for a
heavy imaging load. With the camera's
off-axis guider attached and optional
ﬁlters installed, I was dealing with a 5
lb, 10 oz. imaging package at the scope.
This load was a signiﬁcant factor
with all of my telescopes, but less so
with my William Optics 102-mm f/6.9
refractor. Sliding the camera and telescope forward in the mount's dovetail
saddle offered good balance on my
Losmandy G11 German equatorial. The
real dilemma came when I installed the
camera on my 12½-inch f/4 Newtonian
reﬂector. Its considerable off-axis weight
had to be counterbalanced by adding a
weight to the opposite side and opposite
end of the OTA.

p The large size of the KAF-16200 CCD detector may push the capabilities of fast focal-ratio
telescopes with 2-inch focusers.

p This rear view of the QHY16200A camera with the filter wheel attached shows the cable inputs
and cooling fan. The QHYOAG-M off-axis guider is at upper right. A short 12 VDC cable as well as
several adapters at left are included to adapt the camera to 2-inch focusers (bottom), T-threaded
accessories (middle), and accessories with 54mm threads (top left).

My 12½-inch Newtonian has what I
consider an adequate 2-inch Crayfordstyle focuser, though I had to considerably increase the tension on the
bearings of its drawtube to reduce its
sagging under the QHY16200A's weight.
This sagging produced elongated star
images and focus issues as I moved
the scope to different parts of the sky.
I dealt with some of this by securely
tightening the focuser drawtube thumbscrews, but frankly I wished the scope
had a 3-inch focuser.
The ﬁlter wheel housing has four
¼-20 threaded holes located at each
corner. I attached lightweight steelcable "safety lines" to a couple of these
to ensure the camera wouldn't fall to
the ground should it accidentally slip
from the focuser.
Cable connections on the
QHY16200A are thoughtfully designed.
A clamp with a thumbscrew secures
the USB cable from the host computer,
and a knurled, threaded collar securely
attaches the 12 VDC power cable, but I
wondered why this connection attaches
to a short (40-inch) coax cable rather
than to the camera directly.
On the back of the camera are two
"trigger" connections, two serial ports,
and a ground connection. A 12 VDC

"out" jack is conveniently placed next
to the power input jack. These two jacks
are wired parallel so either may be used
as the 12 VDC input. A 12 VDC cable
with a standard cigarette lighter plug
is supplied, but no AC adapter. The
plug has a convenient rocker switch to
turn power on and off. There's also a
power switch on back of the camera.
When the camera's two-stage cooler is
at 100%, the camera draws 3 amps. A
5 amp 12 VDC power supply is recommended. Finally, the onboard USB hub
allows users to connect an autoguider
camera with a short USB cable. This
means only a single USB cable is needed
between the camera and host computer
- a nice touch.
The imaging chip in the camera is
located 34 mm from the front of the
camera with the ﬁlter wheel connected.
With the OAG-M off-axis guider and
adapter plate installed, the distance
increases to 47 mm - well within backfocus range for most ﬁeld-ﬂatteners and
coma correctors.
Two circular adapter plates come
with the camera. One interfaces with
a 2-inch nosepiece (included) and
standard T-thread accessories. The other
plate has a larger 54-mm-diameter
opening with female 0.75-mm threads.
sk yandtelescope.com * FE B RUA RY 2 018

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Sky and Telescope - February 2018

Table of Contents for the Digital Edition of Sky and Telescope - February 2018