Sky and Telescope - March 2016 - 61

per night. Fast optics are always nice to have, but they
usually exact a premium price on your bank account.
To address that, Sky-Watcher introduced the Quattro
Imaging Newtonian reﬂectors with 8-, 10-, and 12½-inch
apertures. Each is f/4 (hence the Quattro name) and sells
for $610, $770, and $1,199, respectively in the United
States. However, as I found, to make them usable for
imaging you need the optional Quattro Coma Corrector ($285). But even with that added cost, the Quattros
remain bargains for fast astrographic systems.
How well do they work? I tested the 8-inch model, on
loan from Paciﬁc Telescopes in Richmond, Canada, and
found that it worked very well indeed.

Solid Mechanics
The 8-inch Quattro weighs 9.5 kg (21 lbs). Being a large,
solid-tube Newtonian reﬂector, it's prone to catching the
wind and thus needs to be on a sturdy mount for best
performance. I tested it on my Astro-Physics Mach1GTO German equatorial mount, which was somewhat
overkill for this scope. In the Sky-Watcher line, I would
recommend using the 8-inch Quattro with nothing less
than the EQ6 or AZ-EQ6 mounts, and the heavier EQ8
SynScan GPS mount is an even better option.
Since the telescope is designed primarily for photography, key to its performance is the quality of the
focuser. The Quattros use a Crayford-style focuser with
a friction drive and 10:1 ﬁne-speed motion. I found
the focuser precise and rock solid. It locked down well
and never slipped with the DSLR camera I used, nor
with any of the heavy eyepieces I tried when observing
through the instrument.
However, the camera and coma corrector are held in
the focuser with two small setscrews that press directly
on the barrel of the coma corrector. There is no compression ring, nor are the setscrews Nylon tipped, so they
scratched the coma corrector's tube. I also found the
small setscrews tough to get at and adjust. I was also
concerned that they might not be suﬃcient to hold a
heavy CCD camera if the focuser were angled down to
the ground (a common orientation when imaging with
Newtonians). But the Quattro focuser is ideal for DSLRs
and most lightweight CCD cameras.
The Quattro's steel tube has an attractive blacksparkle ﬁnish common to many Sky-Watcher telescopes.
On cool autumn nights, I never noticed any appreciable
focus shift during the one to two hours I needed to
capture a set of images of an object. Even so, it's a good
idea to refocus periodically when imaging through any
telescope, particularly when the temperature changes
markedly throughout the night.
The 8-inch Quattro comes with a Vixen-style dovetail
mounting bar. Its tube rings also include threaded holes
for attaching an additional plate to the top of the scope. I
had no problem bolting on my own, larger dovetail plate

The tube rings included with the Quattro are tapped with
a single ¼-20 thread on both top and bottom, and one ring
includes a ¼-20 threaded stud, suitable for attaching a ball head
for piggyback photography.

The Quattro line includes an excellent 9x50 ﬁnderscope
attached with a standard dovetail shoe, which can be replaced
with a 50-mm guidescope for autoguiding. The Crayford-style
focuser comes with adapters for 1¼- and 2-inch eyepieces. The
2-inch adapter is shown here.

The tube interior is well blackened and contains nine baﬄes, but
does not extend farther than a standard Newtonian. Nevertheless, shooting from a dark site, the author didn't notice any
stray light illuminating the ﬁeld. The coma corrector does not
protrude into the light path, and the only diﬀraction spikes in
images were due to the four-vane spider.

Sk yandTelescope.com March 2016

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Sky and Telescope - March 2016

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