David’s Astronomy Pages
Skywatcher Startravel 120mm (F5) Refractor
I have recently purchased the Skywatcher Startravel 120mm achromatic short tube refractor,
mounted on an EQ3-2 mount. I have a requirement for a non GOTO telescope as I use
my scopes (well, weather permitting!!), at camping/caravanning sites, and although
not really that loud, the whine of the GOTO motors on the Meade and Celestron when
slewing to a target has proved to be a bit of a nuisance on occasions, hence this
purchase.
I ordered the scope online, and it arrived the following morning thanks
to a very prompt and courteous service by Harrison Telescopes. The specification
for this scope is:
•Objective Lens Diameter: 120mm
•Telescope Focal Length: 600mm
(f/5)
•Eyepieces Supplied (1.25"): 10mm & 25mm
•x2 Deluxe Barlow Lens 1.25" (with
camera adaptor)
•Magnifications (with optics supplied): x24, x48, x60, x120
•Highest
Practical Power (Potential): x240
•Direct SLR Camera Connection
•Red Dot Finder
•Dual-Fit
1.25"/2" Focuser
•1.25"/31.7mm Star Diagonal
•Multi-Coated Objective Lens
•EQ3-2
Deluxe Equatorial Mount
•Built-in Polar Alignment Scope Holder
•Aluminium Tripod
with Accessory Tray
The scope came very well packed. Setup was quick and easy, although
having had some years ago an 8" reflecting scope on an EQ3-2 mount. I was familiar
with the mount, its assembly and workings. That said, using the supplied instruction
manual, I would guess that most people could have the entire unit setup with 20 minutes
or so of unpacking it. First impressions were favourable, with the scope and mount
looking and feeling solid and competent. The scope sports the new Skywatcher black
and white colourings, and the equatorial head is now also in white. The new colour
scheme and solid quality of the unit gives the appearance and impression of a much
more expensive item. I carried out some daylight testing of the optics and aligned
the red dot finder unit. Everything so far was good.
Then a miracle happened! On Tuesday
evening, the same day the scope arrived, the skies completely cleared. A new scope
and first light on the very day it arrived! The scope was already on the EQ3-2, so
I simply picked up the assembled unit, (it weighs in at around 20Kgs, so with care
can be moved around), and took it outside to cool down. While cooling down to the
outside temperature, I set the mount to my latitude and approximately polar aligned
it. The EQ3-2 has provision for a polar alignment scope, but this is an optional
extra, so I simply looked through the section where the polar scope would sit until
Polaris was centered through it - not a perfect alignment, but more than good enough
for my visual session.
I started by checking the collimation of the optics via star
tests. The Airy ring patterns produced showed that the alignment of the optics was
more or less perfect. Using the supplied 10 and 25mm modified achromat lenses, I
then moved onto some double stars. All the stars came into focus as sharp pinpoints
of light. Albireo (Beta Cygni) showed off its colours magnificently, and Mizars (Zeta
Ursae Majoris) small, close 4th magnitude companion was easily split using the supplied
25mm lens (24x magnification), while obviously also showing Alcor. With the supplied
10mm lens (60x magnification) Mizar and its close companion had clear black sky between
them. Epsilon Lyrae, the so called ‘double double’ made a magnificent sight through
the eyepiece.
After taking in some beautiful, crisp wide field views of different
areas of the sky, I moved across to the more or less full moon. Clearly a full, or
just past full moon is not the best time for lunar observations, but a clear night
is a rare night at the moment, so I wasn’t about to miss the opportunity. Through
both the 25 and 10mm lenses the moons detail was pinpoint sharp. More surprisingly,
given this is a short tube F5 achromatic refractor, there was some of the expected
chromatic aberration present, but nothing I like expected out of a scope like this.
Inserting the supplied 2x Barlow, the views just got better. Along one limb craters,
illuminated by the reflected sunlight, could be seen rising above the surface, silhouetted
against the dark night sky. Again, even with higher magnification, virtually no chromatic
aberration was discernable.
I continued viewing the moon and stars using other, better
quality lenses than the supplied ones. The optical performance didn’t disappoint
and with the better quality lenses, it really showed that the Skywatcher was indeed
a very well made and put together scope. That isn’t to say that the supplied modified
achromat lenses (which I as I understand it are essentially Kellners) were bad –
they weren’t, and far from it – simply that the other lenses allowed the true quality
of the scopes optics to come through. Using the supplied lenses, I would estimate
that the view was sharp across around 75 – 80% of the field view, and acceptable
out to around 85%. There was, at the outer edges of the view some small distortion
– a very credible performance for a budget priced achromatic scope.
The EQ3-2 mount
proved to be solid base for the scope, easy to set up and use. Tapping one of the
tripod legs produced vibrations in the scope, but these damped down within a second
or so. I have to say that going back to my astronomical roots as it were, that is
using manual controls, star hopping and setting circles, was far more enjoyable than
letting one of my GOTO equipped scopes do it all for me. The GOTOs definitely have
their place and use, but going back to the basics was just simply wonderful – and
manual setup and acquisition of the first target was much quicker and easier than
with the GOTO!
This was only one nights viewing, but based on this I would conclude
that the Skywatcher Startravel 120 on the EQ3-2 performs at a level far higher than
its price tag suggests, is well made, solid and represents excellent value for money.
The only extra that I will get is an RA drive unit to allow objects to be tracked
once aquired, and remain in the eyepiece without having to keep turning the manual
control rod. As these types of drive are silent, no issues when out and about with
it!