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This was the standard
finder supplied with the Sky-Watcher 200 telescope. It's a pretty standard
finder supplied with a range of scopes and also rebadged with various brand
names such as Orion and Celestron.
Out of the box it appears
basic but practical. The focusing is handled by a helical focuser and lock ring
around the objective lens. The rear of the finder has a fixed eyepiece made of
some kind of hard glossy plastic. It was supplied with a standard quick release
finder bracket which has two adjustment screws for aligning the focuser to the
main telescope and a spring loaded screw which keeps the finder under tension
and allows the other two adjusters to control the angle of the finder scope.
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| The standard 8x50 SkyWatcher finderscope as supplied with many of
their telescopes. |
Initial Use
Initially I was quite pleased with the finder. It looks a little plasticky
in parts but works well. Its optics are that of a basic achromatic telescope.
It appears to have a pretty basic lens coating but it's not possible to asses
if the lens edges are blackened as the lens assembly is glued to the front
barrel of the scope. There are knife edge baffles inside the tube. The whole
front barrel is a helical focusing arrangement with a lock ring. To adjust
focus you release the knurled locking ring and then rotate the front of the
finder until you have focus at infinity. Then the lock ring is tightened back
down. It's a simple arrangement which works well.
The cross hairs have a fixed focus but always looked perfectly in
focus to me. The cross hairs do seem quite thick on first impressions.
Experience with the Finder
My first problems using the standard 9x50 became apparent at a dark
sky site. A combination of my poor astro-navigation coupled with the fact that
manipulating a medium sized Newtonian while looking through a finder ablaze
with stars which is also running back to front proved quite difficult.
Manually slewing the telescope towards
the zenith was extremely frustrating I found you constantly end up in yoga like
positions and end up with a severe crick in the neck. This isn't a criticism of
this unit its just a fact of life for any straight through finder.
Its not all bad news though. A straight
through finder does have a lot to offer. Its line of sight is in the same
optical axis as the tube so you can, with practice, use both eyes. One to
navigate the sky and one with a zoomed in view via the finder. This technique
though works best with larger scopes where, at the zenith, you are still more
or less standing straight up. On a small or medium scope you can all too
quickly find yourself bent in half while trying to peer upwards through a small
eyepiece.
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| The SkyWatcher 9x50 mounted alongside the Baader SkySurfer V on my
own SW 200P telescope. |
The thick cross hairs on the Sky-Watcher 9x50,although
looking a bit rough and ready in daylight, tend to be a blessing under a dark
sky as they are easy to see. Finer more elegant crosshairs simply become
invisible under a dark sky without a reticule illuminator and the standard
sky-watcher unit has no fittings to connect an illuminator although Sky-Watcher
do manufacture an illuminated version of this finder.
The optical
quality of the standard 9x50 is rather good with most of the field of view
being in focus. Stars stay sharp across about 70% of the view and the finders
simple but effective focusing works well.
Verdict
A competent finder for those who like
straight through finder scopes. The optics are really rather good and the only
other finder I have tried which pipped the optics on the Sky-Watcher was the
significantly more expensive Stellarvue finder.
Setting the finder up is simplicity itself and the quick release
finder bracket with its spring loaded fitting makes aligning the finder very
simple.
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