Sky & Telescope - April 2021 - 32

S&T Test Report

W Far left: Orion provides the
free StarshootIC cameracontrol software (available
for PC or Mac) and Nautilus
Controller program (near
left) to drive the filter wheel.
While adequate for those
getting started in astrophotography, the two programs
function independently and
do not communicate during
operation, so they can't be
used to program LRGB image
sequences.

images through a single ﬁlter, but then
you must manually switch to the next
ﬁlter using Nautilus Controller. This
makes shooting an entire set of LRGB
frames unnecessarily tedious.
In order to automate an LRGB image
sequence, you'll need to purchase a
third-party camera-control program
and install the ASCOM drivers for both
the G16 and Nautilus ﬁlter wheel. I
used Maxim DL for my color imaging
sequences, though other options include
Astrophotography Tool, Sequence Generator Pro, NINA, or the camera-control
plugin for TheSkyX.
The StarShoot G16's 12-bit analogto-digital converter combined with its

20,000e- full-well capacity is less than
a modern DSLR, which is typically
14-bit, or CCD cameras, which often
are true 16-bit devices. But while this
might sound detrimental, in practice
the images looked just as good as other
deep-space cameras I've reviewed. The
StarshootIC software saves single images
produced by the camera as 32-megabyte
FIT ﬁles, and can also save TIF, JPG, or
PNG ﬁles, or SER video formats.

Performance Under
the Stars
Orion claims the G16's 2-stage thermoelectric cooling (TEC) is capable of
achieving stable temperatures of up to

S When paired with the author's 71-mm refractor, the G16 produces colorful images of deep-sky
targets like IC 434, the Horsehead Nebula, seen above. This image consists of 45-minutes exposure through each of four filters for a total of 3 hours.

APRIL 2 021 * SK Y & TELESCOPE

40°C below the ambient temperature.
This further reduces thermal noise in
the CMOS detector to produce smooth,
speckle-free images. Setting the TEC
value to -25°C when the ambient
temperature was 16°C (60°F) produced
reliable performance with the cooler
operating at 65% power. The manual
warns that some dew may form on the
chamber window when the camera is
operated at the extreme end of the TEC
cooling range, though I didn't experience that during my tests.
During operation, the Nautilus ﬁlter
wheel produces a low hum as each ﬁlter
rotates into position. I was impressed
with the generous aperture of the camera housing and ﬁlter wheel. The close
proximity of the 48-mm ﬁlters to the
camera's detector in conjunction with
the 48-mm threaded opening on the
front of the ﬁlter wheel didn't introduce
vignetting even with fast optical systems
and their inherently steep light cones.
With the ﬁlter wheel attached, the
camera's total back-focus distance is
about 44 mm, which is plenty of room
for use with most ﬁeld ﬂatteners and
coma correctors (as well as the necessary adapters), which typically require
55-mm spacing from the detector for
best performance. Introducing an offaxis guider (OAG) in the lineup and
maintaining optimum spacing may be
challenging depending on the depth
of the unit. Thinner OAGs mounted
between a ﬁeld ﬂattener or coma corrector will work best.
It should be noted that the StarShoot G16 doesn't include a mechanical shutter, so you need to cover the

Sky & Telescope - April 2021

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