WWW.ASTRONOMY.COM 61the lunar surface looked incredibly sharp.
Contrast was also striking, with jet-black
shadows against a sunlit surface of varying
shades of white and gray. There was some
minor purple fringing visible around some
of the starkly lit crater rims on this unfor-
giving target, but it was barely noticeable
against such an impressive scene.
Some quick photos of the Moon
through the Evostar confirmed my visual
impression and were among the sharpest
I’ve ever taken. The minor color fringing
around some of the crater rims was also
evident in the photos, but not nearly
enough to spoil anything. For a reality
check, I later posted some on social media
just to gauge reaction. The comments were
all enthusiastically positive, with lots of
happy emojis littering my wall.Next, we aimed at Saturn. Despite the
planet’s low altitude at the time, the image
was sharp. The dual-speed focuser proved
its worth when we cranked up the magnifi-
cation to 200x. Both the Cassini Division
and the delicate C (Crepe) ring were evi-
dent, as was the planet’s shadow cast onto
the rings. The dual-speed focuser’s coarse
motion was even and smooth, without any
binding or slippage, as was the fine focus.
Star testing on a couple of randomly
chosen 3rd-magnitude stars (a good bright-
ness level for the aperture) showed identical
diffraction patterns on either side of focus,
proving the objective was well figured and
collimated. To push the color correction of
the apochromat, I aimed toward brilliant
Vega. Like the Moon, Vega displayed some
minor bluish residual color. But the in-focus
diffraction rings were spot on.
Continuing the sightseeing, globular
clusters M13 and M15 were both nicely
resolved at 133x. I was especially impressed
that M13 revealed its unusual “propeller.”
This feature is formed by three subtle dark
lanes just off center from the cluster’s core
that form the letter Y, or as many call it, a
propeller. (See July 2018’s Reader Gallery for
an image that shows the feature, taken by
astrophotographer Rodney Pommier.)
Normally, the propeller is challenging
through 8- to 10-inch apertures, but it was
evident in the Evostar 150, thanks to the
optical system’s high quality. I have never
seen it through a scope this small before.
The Dumbbell Nebula (M27), the Ring
Nebula (M57), and the Little Dumbbell
Nebula (M76) were equally impressive.
Viewing each at 133x, they all showed more
detail than I would expect from a 6-inchscope. I was especially taken by the ethereal
appearance of the Ring and how it seemed
to f loat among a starry field with a black
backdrop.
Everything we viewed through the
Evostar 150 was sharp with superb contrast.
Colors in objects such as the gold-and-blue
double star Albireo (Beta [β] Cygni), as well
as the ruby jewels hidden among the sap-
phires of the Double Cluster (NGC 869 and
NGC 884), were beautifully displayed.
Under steady seeing, the Evostar handled
high magnification well. The four stars that
make up the Double-Double (Epsilon [ε]
Lyrae), for instance, were cleanly separated
as four distinct pinpoints at more than 400x
when seeing was steady. Still tighter pairs,
like 53 Aquarii, at magnitudes 6.3 and 6.4
separated by 1.5", were also resolvable. But I
cannot definitively say that I could detect
the duplicity of Struve 2751 (Σ2751) in
Cepheus, another test target. Those stars are
separated by 1.0", which is close to this aper-
ture’s theoretical limit of how tight a double
star it can separate. Based on what I could
see, however, I bet it’s doable with this scope
under better seeing.The bottom line
All in all, I came away highly impressed
with the Sky-Watcher USA Evostar 150DX.
Outstanding optics, combined with excel-
lent mechanics and a price that’s a fraction
of some of the other APOs in the field,
make this an excellent choice for anyone
looking for a large refractor.USA’s EvoStar 150
Phil Harrington is a contributing editor of
Astronomy who gets excited every time he looks
through a high-quality scope at a sky object.Sky-Watcher USA Evostar 150DX
Ty p e: Apochromatic refractor
optical tube assembly
Focal length: 1,200 millimeters
Focal ratio: f/8
Weight: 22 pounds (10 kilograms)
Length: 50.5 inches (128 centimeters)
Comes with: 3.4-inch rack-and-pinion
focuser, tube ring hardware,
aluminum case
Price: $2,800
Contact: Sky-Watcher USA
475 Alaska Avenue
Torrance, CA 90503PRODUCT INFORMATION
The Evostar 150DX
is a 6-inch f/8
apochromatic
refractor. Its two-
element objective
features one element
made from extra-
low-dispersion glass.
SKY-WATCHER USA