Hioptic
6" Maksutov Cassegrain NMC1900x152
Telescope Review
HiOptic
152 > First Light
FIRST LIGHT
TERRESTRIAL OBJECTS
After aligning the finder scope with the OTA the first object to try
was
the cockerel weather vane on top of the church 1km/0.6mi away. The
image below was
taken though a Meade 40mm Super Plossl lens. The supplied 20mm lens was
tried but it was
unable to
come to a sharp focus. The weather couldn't decide between sun or
thunder and
the seeing was difficult so this was put down to bad seeing. It is
worrying however that Hioptic don't provide an eyepiece wide enough to
cope with all seeing conditions as an inexperienced telescope user
might assume their telescope was broken!
UPDATE: Having tested on a day with clearer conditions a full range
of eyepieces from 40mm-6.4mm have been now been used. With the 6.4mm
the beak of the bird filled the view in the eyepiece and was clear and
sharp.
When it became dark, seeing was still poor, and clouds covered the
night sky. However, about 8km/5mi in the distance, below the cloud
line, the local TV mast lights
could be
seen and these were used for the first dark tests.

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Sub 1
second exposure.
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15
second exposure.
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The light gathering ability was impressive for a Maksutov with a 15
second exposure looking like it was taken in day conditions. The images
showed noticeable tripod wobble indicating the EQ3 would be difficult
to
use for even basic astro imaging. The lights in the image also showed
noticeable blooming (star lashes) which is probably due to the the lack
of anti-reflective corrector
coatings. This however, is a question of taste, some people like
pinpoint stars, but some prefer a more artistic star and even resort to
Photoshop to add them! A user could always use eyepiece filters to
reduce this effect if they didn't like it.
MOON
Early in the evening the moon put in a brief appearance while darting
in and out of the clouds. The views through the scope were very sharp,
and where the craters cast a shadow, they were very rich in detail. It
didn't appear so bright that it would require a moon filter. At 40mm,
it took up the whole eyepiece and the supplied 20mm was unable to
put the whole moon in the eyepiece. There were no signs of of blue and
red fringing around the edges using the eye. Sadly the seeing
conditions were not good enough to try out the 6.5mm eyepiece.
JUPITER
Later that night Jupiter came up above the horizon and there was just
enough time between the clouds to catch a glimpse.
The view was too bright in both 40mm and 32mm eyepieces.
The eye could see a big white circle (Jupiter) and 4 bright dots (it's
moons). Colour fringing was obvious, but maybe just the result of an
over bright image, being low on the horizon and bad air conditions.
Normally this
reviewer would reduce the brightness by using more
zoom with
a closer lenses but these were unable to get focus due to the poor
seeing conditions. It was clear that Jupiter on these wider lenses
would benefit from a planet or moon filter. It was so bright any
details were being
washed out. The manufacturers
specification suggested including
sun and moon filters but none was supplied with this kit.
The image below was a single frame captured on a Casio QV-2900UX
digital camera. Even on the camera the image was
too bright so the cameras zoom and high shutter
speed were used to reduce the glare.
The four moons in the image above may be hard to see if the reader
is viewing in a bright room.
STARTEST
A few days later conditions cleared enough to do a star test on
Capella. Capella is the 6th brightest star in the night sky and through
this scope twinkled and showed signs of beginning to bloom. Other stars
nearby just exhibited the pin sharp white dots you would expect from a
Maksutov. With Capella centred in the eyepiece it provided near perfect
collimation defocused circles so there doesn't seem to be any issues
with collimation on this scope.
SUMMARY
Despite the poor conditions the views from this telescope looked very
promising. It provided typical sharp Maksutov optical views on rich
dark backgrounds despite the reviews light polluted sky. It does seem
to have a bit of blooming on very bright
objects, maybe the result of lack of corrector coatings. There also
seems to be a bit of colour fringing. I'm putting this down to the
objects being low on the horizon and suffering air de-fraction, for
now, until the weather gets better.
Summer is
never a good season for testing a scope so expect an update to this
review in the winter when hopefully we can split some stars and try
some DSOs (Deep Sky Objects).
SECOND LIGHT
On a slightly clearer night a better shot of a nearly full moon was
taken. There was a little colour fringing with a small amount of blue
at
the top and red on the bottom. The moon was still low on the horizon so
we can't rule out this being the result of air de-fraction yet.
THIRD LIGHT
A few days later the moon was
higher in the sky and no signs of colour fringing were noticed in
either the eyepieces or camera image so we can definitely put this
effect down to low atmosphere conditions and not the scopes optics.
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