Sky and Telescope - May 2015 - 71

Two small fans dissipate heat from its regulated
cooling system, providing stable cooling down to 38°C
below ambient. An internal USB hub allows the autoguiding camera, called the Atik GP, to be plugged into a
USB port on the camera housing with a short USB mini
cable. This reduces the number of long cables dangling
from the camera: a USB 2.0 line connected to your
computer, and the camera's 6-foot-long, 12-volt DC power
cable terminating in a cigarette lighter-style plug. Atik
One's ﬁve-position ﬁ lter wheel is completely internal and
requires no additional power or connecting cables.
The Atik One has no mechanical shutter, so users are
required to cover their telescope when recording dark
and bias calibration frames, which can limit its use as
a remote imager. However, if the camera's ﬁfth ﬁlter
wheel position isn't needed for a ﬁlter in your imaging
plans, ﬁ lling that position with an opaque ﬁlter would
provide an improvised internal shutter for dark frames.
Because of its regulated cooling, a dark-frame library can
be created for use on future nights.
Two ¼×20 threaded tripod mounts are located on
opposite sides of the camera, providing users the ability to mount the unit when using camera lenses with
a third-party lens adapter. I used one of these tripod
sockets to secure a makeshift "safety line" to the camera
to ensure it wouldn't fall to the ﬂoor if it slipped from my
telescope's focuser.
Out of the box, the Atik One comes with an adapter
plate with a standard female T-thread held by three
screws to the camera's front housing. A supplied 2-inch
nosepiece screws into this adapter plate. This front plate
needs to be removed to install the oﬀ-axis guider.
Atik provides separate manuals for the main camera,
the oﬀ-axis guider, and the GP guide camera, and a PDF
document is available on the company's website with
instructions describing how to assemble the entire system. While assembling the oﬀ-axis guider, I ran into my
ﬁrst minor hurdle to surmount - the supplied screws
were too short!
After rounding up some metric M3 screws of sufﬁcient length to attach the guider to the camera body, I
then attached the GP camera with its T-threads onto the
oﬀ-axis guider and connected the unit to the main body
using the supplied short USB mini cable.
Imagers familiar with autoguiding should note that
the Atik GP camera includes no direct connection to
your telescope mount, such as an industry standard
ST-4 compatible port, to allow guiding commands to be
sent directly to your mount's drive motors. An additional interface device is required, or you'll need to use
a third-party control software such as MaxIm DL that
has an option to send guiding commands to your mount
through the main camera interface. I used a Shoestring
Astronomy GPUSB adapter (shoestringastronomy.com)
that I had on hand.

Under the Stars
Once I ﬁnally had everything conﬁgured, "ﬁrst light"
with the system went very well. I began by testing the
camera on my 12½-inch f/4 Newtonian reﬂector ﬁtted
with a Baader MPCC coma corrector. The Atik One's
short 47-mm back focus with its oﬀ-axis guider easily
reached focus in my telescope's low-proﬁle Crayford-style
focuser, with room to spare. I was concerned that the
1¼-inch color ﬁlters might cause some vignetting with
such a fast telescope, but the camera's integrated ﬁ lter
wheel places the ﬁ lters so close to the main detector that
this was never a problem.
Even with the oﬀ-axis guider's small pick-oﬀ prism,
ﬁnding a suitable guide star was never a problem, owing
to both the sensitivity of the Atik GP guider camera
and the fast f/4 system I was using. The oﬀ-axis guider
uses a large knurled wheel that allows quick and precise
focusing of the guide camera without rotating the GP
camera, a well-thought-out feature for oﬀ-axis guiders.
Using the supplied Artemis software to operate the
Left: The camera
housing contains a
slim, internal ﬁlter
wheel that accepts
standard 1¼-inch
color ﬁlters (not
included), though
the camera does
not incorporate an
internal shutter.
Users may want to
consider ﬁlling the
5th ﬁlter slot with an
opaque ﬁlter to use
when recording dark
and bias calibration
frames.
Bottom: Even with
its oﬀ-axis guider
and internal ﬁlter
wheel, the Atik One
takes up very little
focus travel (requiring a total of 47 mm
of additional focus
travel), allowing it
to be used with fast
Newtonian reﬂectors such as the
author's 12½-inch
f/4 with a Baader
coma corrector.

Sk yandTelescope.com May 2015

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Sky and Telescope - May 2015

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