S&T Test Report
72 JANUARY 2020 • SKY & TELESCOPE
ens the effect of coma,
an optical aberra-
tion that makes stars
toward the edge of the
fi eld look blurred and
misshapen. Not only
were objects sharp
at the center of the
fi eld of view, but also
toward the fi eld edge.
Jupiter, for example,
showed a wealth of
atmospheric detail at
209 ×, including small
features within its
belts and zones.
The visibility of
details on a planet
is a stringent test
of the quality of a telescope’s optics,
and this scope showed itself to have
optics as good as those of any 8-inch
Schmidt-Cassegrain Telescope I’ve used.
Naturally, deep-sky objects like globular
clusters were subdued from my light-
polluted backyard, but the ACF’s sharp
optics helped immensely while resolving
star clusters. Messier 13 wasn’t just a
dim blur; it showed itself to be a globe
of tiny stars.
Like most SCTs, the 8-inch ACF
focuses by moving the main mirror
when the focus knob on the scope’s rear
cell is turned. There was some focus
shift as I moved back and forth through
focus, but it was small and I estimatedit to be less than 30
arcseconds.
As the evening pro-
gressed, I forgot I was
working on a prod-
uct review and just
enjoyed myself visiting
dozens of deep-sky
favorites. At the end
of my tour (Audio-
Star contains a list of
ready-made sky tours), I took a break to
see if a more accurate polar alignment
would also improve the mount’s Go
To pointing accuracy. After additional
tweaking, objects were close to the cen-
ter of the 25-mm eyepiece at 80× and
at least in the fi eld of a 12-mm ocular
at 160×. The improvement was enough
that I strongly recommend the purchase
of the optional polar-alignment scope.
Not only did the LX85 GEM display
impressive Go To accuracy, it was also a
quiet experience even at its top slew-
ing speed of 4° per second. I was also
impressed by the mount as it reached its
targets. A rap on the telescope tube pro-
duced vibrations that died out in aboutthree seconds, which I consider good.
Comfortable with the LX85’s Go To
performance, I explored the AudioStar’s
other features. Foremost is the reason
for its name; it contains audio fi les
for many of the objects in its library.
When observing M13, for example, I
was treated to a presentation on the
star cluster. If you tire of hearing these
mini lectures, the AudioStar can be set
to deliver them on demand instead of
automatically.
In addition to the guided tours, the
AudioStar hand paddle includes nine
selectable slewing speeds, a serial port
for communications with a PC, a library
of 30,000 targets, and even a built-in
red fl ashlight.Guiding Performance
Long-exposure deep-sky astrophotog-
raphy is the most demanding test of a
mount. The night I chose to shoot M13
wasn’t perfect — there was plenty of
haze and a fat Moon hanging in the
east. But I wasn’t looking to capture a
beautiful portrait of the cluster. I just
wanted to see how well the LX85 tracks.
After installing Meade’s AutoStar
Suite planetarium simulator on my
PC laptop, I connected it to the LX85
using a Meade-compatible serial cable
I had on hand. Once a connection was
established, I was able to send the tele-
scope to targets using the planetarium
software. Clicking on a target onscreentThe AudioStar Go
To controller includes a
30,000-object database
with descriptive presenta-
tions and several alignment
routines, though only the
Easy Align mode is de-
tailed in the manual.qLeft: As delivered, lining up the home position markings on the declination axis causes the axis clutch lever to impact the motor box. Right: Turning
the head 180° to match the illustrations in the manual (and Meade’s website) allowed for successful Go To alignment.