Skyscout Scope 90
A fun combo - finding objects
has never been so cool!
By Erik Wilcox
Since its release, everyone seems to be
talking about the Celestron SkyScout
Personal Planetarium. On its own, it’s an
innovative and useful tool for locating and
identifying a large assortment of objects in
the night sky. But one question I kept
hearing on all the astronomy message
boards was, “Can I mount it to my telescope and use it as a manual 'go-to' system?” The short answer was no, if the telescope’s optical tube was made out of steel.
The reason is that the SkyScout relies on
GPS satellites to find objects, and magnetic sources can cause interference.
Well, Celestron must have been listening. The new Celestron SkyScout
Scope answers the question by employing
a non-magnetic aluminum optical tube,
finderscope, focuser, tube rings, and
SkyScout mounting hardware, so magnetic interference isn’t an issue. But how well
do the SkyScout and scope work together?
First, I’ll begin with the scope itself,
since the ability to find objects would be
useless if the views through the eyepiece
weren’t any good. The scope in question is
a 90-mm f/7 achromatic refractor. It
arrived in a large, well packed box, complete with everything needed to get outside and view on the first night. …That is,
if the skies were clear! The new gear
“curse” was certainly with me, as it seemed
to be cloudy every evening.
While this did allow me to get
accustomed to many of the SkyScout’s
unique features, it wasn’t as satisfying
as actually getting some observing
time in! I spent a good deal of time with
the scope set up in my living room, ready
to go at the first sign of a break in the
clouds. It’s a nice looking scope, and it
really got me thinking about how much
gear money can buy these days. For just
over $300 (not including the SkyScout
itself), this was a nice, solid rig. The
mount has thick, stainless steel legs; the
optical tube is built well and attractive to
look at. Anyone would be proud to own
such a scope and its appearance and overall quality gives the impression of a much
higher price tag.
For specifics, I’ll start with the
focuser. For an inexpensive telescope, the
R&P focuser is very smooth with no
“slop” or play. However, I’d like to see a bit
more outward travel than the 2 3/8 inches offered. Some of my eyepieces didn’t
reach focus until the drawtube was
extended almost all the way out and new
owners should consider investing in one
of the short extension tubes that are readily and affordably available. The 6x30
finderscope is of good optical quality,
although it did arrive out of focus.
Focusing it was easy, by loosening a locking ring on the finderscope body, and
turning the achromatic
lens assembly clockwise or
counterclockwise until stars are
in focus. Then, the locking ring is
tightened down to maintain its
The scope comes with two eyepieces,
a 40-mm, and a 10-mm. Both appear to
be of a Plossl design, and they’re about
what I’d expect as accessories included
with a telescope. The 10-mm is optically
good, with tight eye relief that’s typical in
shorter Plossls. I found the 40-mm difficult to use, as the eye relief is extremely
long. Even with the eyeguard peeled up,
kidney beaning and “blackouts” were an
issue for me. However, an eyeglass wearer
might find the long eye relief in the 40mm useful. Both eyepieces are internally
blackened, and I could detect no stray
reflections. The 40-mm has a safety
groove on the barrel.
A 1.25-inch 90 degree prism diagonal
is also included. After comparing it with
my own mirror diagonal, I was pleasantly
surprised. The prism diagonal shows no
visible loss of brightness, and works well
for astronomical viewing.
Under a suburban sky, I had several
fun and productive nights out with the
SkyScout scope. At high power, Mars
revealed its slight gibbous phase and a
good amount of detail on its disk. The traAstronomy TECHNOLOGY TODAY
pezium in Orion was crisp and clear, and
easily showed its four main components.
Deep sky objects were as good as could be
expected for a 3.5-inch scope in a suburban sky. Objects like the Double Cluster,
the Pleiades, and M35 were beautiful to
view. This refractor really excels with
brighter open clusters. Even in my poor
sky, it was a nice viewing companion on
these objects.
I quickly determined that the optics
on this particular scope were excellent. It
takes magnification very well, and a
Ronchi film strip test revealed straight,
crisp lines, with no spherical aberration.
Chromatic aberration wasn't bad at all
either, considering that this is an f/7
achromat. The moon had a slight bluishviolet tinge along the limb, and a bit of
false color could vaguely be seen on bright
stars as well, but it wasn’t particularly
Staring down the optical tube, everything looked nice and blackened, with the
exception of the three screws used to
mount the lens cell. Removing the dew
cap (which snaps off easily) accesses the
screws, and it would be easy to take them
out and paint them flat black, should one
desire to do so. As is, I didn’t note any
glare from these screws during my observing sessions.
The Alt/AZ mount, though very
beefy for a scope of this size, did get a bit
shaky when attempting to focus objects at
higher powers. This was mainly the case
when the SkyScout was mounted on top
of the telescope. A solid rap on the side of
the tripod required just over five seconds
for the shaking to dissipate. Owners
should consider investing in Celestron's
very effective anti-vibration tripod pads –
these should help tame vibration and significantly reduce those five seconds.
The mount is certainly much more
solid than many of the comparable aluminum leg tripods I’ve used, and the
unique clutch mechanism works well. In
fact, it’s far better than an alt/az mount
that I recently owned, where balance was
a real problem depending on where the
scope was pointed. With this mount, the
same lever that moves the scope up or
down in altitude is also used to lock its
Continued on Page 58
Celestron SkyScout Scope
• Designed with non-magnetic
materials that do not to interfere
with the SkyScout sensors.
• Quick and easy no tool setup.
• 90-mm refractor optical design with
all coated glass optics and 660-mm
(f/7) focal length for crisp, clear
• Erect image 6x30 finderscope with
quick-release bracket.
• Erect image optics are ideal for
terrestrial and astronomical use.
• Pan handle control with clutch for
smooth and accurate pointing.
• Rugged pre-assembled tripod with
1.25" stainless steel tube legs
provides a rigid and stable viewing
• Accessory tray for convenient
accessory storage.
• Adjustable bracket to hold SkyScout
(SkyScout Personal Planetarium sold
90 mm (3.54 in)
660 mm (25.98 in)
40 mm (1.57 in)
16.5 x
10 mm (0.39 in)
66 x
Fully Coated
6x30 Erect Image
Erect Image diagonal -1.25"
The Sky L1
213 x
1.54 arc seconds
1.29 arc seconds
165 x
3 degree
158 ft (48.16 m)
25 in (635 mm)
20 lb (9.07 kg)
The SkyScout Scope is currently available from your favorite Celestron dealer for $299.
Celestron has made
it easy to attach and
align the SkyScout to
the Scope 90 with a
specially designed,
no tools required
adjustable mount.
Continued from Page 56
position. This is done by simply turning
the end of the lever clockwise - a very nice
feature. In azimuth, there’s an easily
accessible lever on the mount that can be
Celestron has now introduced the new
SkyScout Connect which allows the
SkyScout to be connected directly to
Celestron computerized telescopes. Now
Celestron owners can use the SkyScout to
locate any object in its database and their
computerized telescope will slew to the
same object with a touch of a button.
tightened to lock position. Aside from a
small amount of backlash in altitude, the
clutch system works flawlessly.
The only issue I have with the mount
is that it’s not possible for the scope
to point directly at the zenith.
Attempting to do so causes the optical
tube to make contact with the mount. I
was finally able to view at the zenith by
adjusting two rear tripod legs so they were
a few inches shorter than the front tripod
leg, but doing this makes the viewing
position a bit difficult. I’d like to see
Celestron offer an aluminum “wedge”
that could be bolted onto the existing
dovetail bracket for easier viewing at the
zenith, although it sounds like something
enterprising ATMers will have no
problem creating.
As for the SkyScout Personal
Planetarium, well, it’s a lot of fun! The
unit mounts onto the telescope with a
pre-installed bracket and threads on with
a single thumbscrew. Three other protruding knobs fit into the SkyScout’s
body, further holding it in place. And the
bracket itself is adjustable, so that the
SkyScout can easily be aligned with the
main telescope.
With the included earbuds, an audio
description of many objects can be
played. This proved very useful and adds
to the excitement of the object being
viewed. There’s also a text description
which can easily be scrolled through.
The whole unit is very user friendly.
The buttons are large and the screens are
easy to navigate. The red backlight has an
adjustable brightness level, so it won’t
destroy your night vision. Finding objects
is quick and simple. They’re all catego-
rized, so it’s easy to pick an object out of
the database. Looking though the large
viewfinder, it’s then easy to “zero in” on
an object, and multiple red arrows lead
the way. When an object is centered, all
the arrows illuminate. There’s a “Target”
button to quickly identify objects, a USB
port to download updates from a computer, and a Sky Tour/SD card slot for
interactive tours of the sky (with optional
Sky Tour cards).
The unit is made of lightweight, high
impact plastic, and has rubber armor for
an easy grip, even when wearing gloves.
From a design standpoint, it would be
difficult to improve on the SkyScout’s
ease of use.
The SkyScout uses GPS satellites to
find its way and thus needs an unobstructed view of the sky. I found that
accuracy was compromised when I
attempted to use it near buildings and
trees. In addition, a magnet icon comes
on to let you know when you’re too close
to a magnetic source, such as a vehicle.
Getting the icon to deactivate requires
moving at least 6 to 8 feet away from the
With an unobstructed sky, the accuracy worked well for aligning the scope.
Objects located in the SkyScout were
usually within the field of view of a low
power eyepiece, or visible in the finderscope. Using the SkyScout by itself on
showpiece objects, stars, etc., gave good
results too. The multi-coated viewfinder
doesn’t seem to diminish the brightness of
objects when compared to just viewing
them with the naked eye.
Battery life is pretty good and is
aided by a feature that shuts the SkyScout
off after a few minutes of inactivity.
Turning the unit back on requires it to go
through the GPS acquisition process
again. However, this only takes a minute
or two, so it’s probably a more than fair
trade for the savings in battery power.
Overall, I found that the Celestron
SkyScout scope matched up well with the
SkyScout Personal Planetarium. As
opposed to just having a telescope with a
built-in push-to system, this combination
allows the user to enjoy the SkyScout on
its own as well and to own both at a very
modest price. Kudos to Celestron!