http://www.skyandtelescope.com.au 67telescope objective. Camera drivers,
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-anodised camera body
measures 15 cm square and 7 cm deep,
including the 75-mm-diameter fan on
theback.Thefilterwheelhousingis21
cm square by 3.1 cm deep. The QHY off-
axisguidertakesupanadditional112
mm of back focus.
Whenitcomestochipsize,housing
dimensions and weight, the QHY16200A
is the largest astronomical camera I’ve
used,anditmadeforaheavyimaging
load.Withthecamera’soff-axisguider
attached and optional filters installed,
Iwasdealingwitha2.5-kgimaging
packageatthescope.
Thisloadwasasignificantfactor
withallofmytelescopes,butlessso
with my William Optics 102-mm
f/6.9refractor.Slidingthecamera
andtelescopeforwardinthemount’s
dovetail saddle offered good balance
on my Losmandy G11 German
equatorial. The real dilemma came
whenIinstalledthecameraonmy
31.8-cmf/4Newtonianreflector.Its
considerable off-axis weight had to be
counterbalancedbyaddingaweightto
theoppositesideandoppositeendof
the OTA.
My 31.8-cm Newtonian has
whatIconsideranadequate2-inch
Crayford-style focuser, though I had to
considerably increase the tension on
thebearingsofitsdrawtubetoreduce
itssaggingundertheQHY16200A’s
weight. This sagging produced elongated
starimagesandfocusissuesasImoved
thescopetodifferentpartsofthesky.
I dealt with some of this by securely
tightening the focuser drawtube
thumbscrews, but frankly I wished the
scopehada3-inchfocuser.
The filter wheel housing has four
¼-20 threaded holes located at each
corner. I attached lightweight steel-
cable‘safetylines’toacoupleofthese
toensurethecamerawouldn’tfallto
thegroundshoulditaccidentallyslip
from the focuser.
Cable connections on the
QHY16200A are thoughtfully designed.
Aclampwithathumbscrewsecures
theUSBcablefromthehostcomputer,
andaknurled,threadedcollarsecurely
attachesthe12VDCpowercable,butI
wondered why this connection attaches
toashort(1metre)coaxcablerather
than to the camera directly.
Onthebackofthecameraaretwo
‘trigger’connections,twoserialports,
andagroundconnection.A12VDC
‘out’jackisconvenientlyplacednextto
thepowerinputjack.Thesetwojacksare wired parallel so either may be used
asthe12VDCinput.A12VDCcable
withastandardcigarettelighterplug
is supplied, but no AC adapter. The
plug has a convenient rocker switch to
turnpoweronandoff.There’salsoa
powerswitchonbackofthecamera.
Whenthecamera’stwo-stagecooler
isat100%,thecameradraws3amps.
A5amp12VDCpowersupplyis
recommended. Finally, the onboard
USBhuballowsuserstoconnectan
autoguider camera with a short USB
cable.ThismeansonlyasingleUSB
cableisneededbetweenthecameraand
hostcomputer—anicetouch.
The imaging chip in the camera is
located34mmfromthefrontofthe
camerawiththefilterwheelconnected.
With the OAG-M off-axis guider and
adapter plate installed, the distance
increasesto47mm—wellwithinback-
focusrangeformostfield-flattenersand
coma correctors.
Twocircularadapterplatescome
with the camera. One interfaces with
a 2-inch nosepiece (included) and
standard T-thread accessories. The other
platehasalarger54-mm-diameter
openingwithfemale0.75-mmthreads.
Both are secured to the filter wheel
housing/QHYOAG-M with six M3
Phillips screws. Tools are included with
thecameratoallowremovalofthefilter
wheel cover to permit installation of up
to seven 50-mm filters.SThis 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 54-mm threads (top left).SThe large size of the KAF-16200 CCD
detector may push the capabilities of fast
focal-ratio telescopes with 2-inch focusers.