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Old 04-11-2007, 04:01 PM
gary
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gary is offline
 
Join Date: Apr 2005
Location: Mt. Kuring-Gai
Posts: 5,916
Observing with the Obsession 18 Ultra Compact

Firstly, a disclaimer. The following post relates to a product of Obsession
Telescopes. Obsession are a customer of Wildcard Innovations and buy our
Argo Navis Digital Telescope Computer.

Dave Kriege will be a name well known to many of you. Dave is owner
of Obsession Telescopes and co-author of "The Dobsonian Telescope",
a book many regard as the bible of large truss pole telescope design.

Earlier this year, Dave generated quite a lot of excitement when he announced
he would be introducing a new telescope to the Obsession range. He kept the
lid on what the scope would look like, so many of us were anxious to see it
when he brought the pre-production prototype to the Texas Star Party (TSP) in
May this year.

In the early morning hours of my first night at TSP, I was able to track Dave
down on the observing field. "Come and take a look at this", he whispered to
me. Opening up a modest size box, I was stunned to see inside a complete
18" aperture truss pole Dobsonian telescope in its 'knocked-down' state. It was so
compact, it was evident it would fit into the boot of just about any car.

The next day, to a packed meeting hall, Dave introduced the new 18" f'4.2 UC
(Ultra Compact). When he assembled the scope in under three minutes
there was an enormous ovation.

Whist at TSP, I had a brief opportunity to use the scope and was convinced
straight away that Dave had made no compromises when it came to the
performance of the instrument.

Therefore when Dave brought a production version of the 18 UC to Australia
last month, I was excited about the prospect of getting to use it again, this
time under dark Australian skies near Coonabarbran for a week.

In the back of my Subaru Forester, I had transported up one of Andrew Murrell's
scopes, a classic 18" f/4.5 Obsession fitted with Argo Navis and ServoCAT.
The classic f/4.5 18 fits into a car like the Forester if you fold the back seats
down, but it takes up a lot of space and I avoid lifting the mirror and rocker box
on my own. The optical and mechanical performance of the classic 18 is
par excellence and anyone who has ever used an Obsession instantly
understands what premium telescopes these are.

Dave assembled the f/4.2 18 UC a few meters away from the classic f/4.5 18
I was using, so it was convenient to go back and forth between the two scopes
to make comparisons.

What was instantly evident was that the new 18 UC was delivering exactly the
same quality views as the classic 18. That comes as no surprise as both scopes
have the same quality 2" thick mirrors that come from a choice of Galaxy or OMI,
supported by 18 point mirror cells and coupled with high quality secondary
mirrors along with refinements such as Feathertouch focusers.

Dave had also brought with him a couple of new TeleVue 13mm Ethos
eyepieces, which I had also first used at TSP whilst we spent an night observing
with Al Nagler. These were wonderful 'cruising' eyepieces for the 18" scopes
and the views of the Tarantula were probably the most stunning I had ever seen.

To see how the new 18 UC would fit into the Forester, I folded the back seats up
and the virtual mirror box when placed inside the rocker fits in easily. In fact,
the scope is likely to fit into the boot of just about any car. The virtual mirror
box and rocker measure 61cm x 61cm x 34.3cm high. The only other component
was the clever inter-connected 6 pole truss which slid into a cardboard
tube for transport. These were longer than the Forester's boot, but easily
fitted between a couple of passengers in the rear seat or optionally on the
roof rack. The good news is that the heaviest component of the scope to lift
was the 28kg virtual mirror box and mirror. Since this particular component is
so compact and therefore not awkward, this is something I could lift on my
own if taking care. The eyepiece height at the zenith is 180cm, so a vertically
challenged individual such as myself only requires a very short step ladder
which again is not a problem to transport in the boot of just about any car.

The bottom line - here is a reflector with 18 inches of high quality optical
performance and fabulous mechanical performance that will fit into the
boot of just about any car and which can be lifted out of the car and assembled
in just a few minutes by the average bloke on his own.

In this post and some posts below, I have attached some photos I took
showing the 18 UC in the back of the Forester and Dave lifting it out.
One image also shows the telescope in an optional Air Transport Association
(ATA) compliant travel case. I have also attached some photos showing the scope
in various stages of assembly. In the background can be seen a couple
of other Obsessions, a 25" and a classic 18.

Dave tells me the 18 UC is now in production. He and some American
observing colleagues who had also flown out for the week were audibly
gasping as they cruised the regions in and around the SMC and LMC.
When we Aussies hosting them looked through the same 18 UC fitted
with Ethos, we started making the same noises, despite the fact these
were familiar skies to us.

Best Regards

Gary Kopff
Mt, Kuring-Gai
Attached Thumbnails
Click for full-size image (18uc_1_med.jpg)
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Click for full-size image (18uc_2_med.jpg)
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Click for full-size image (18uc_3_med.jpg)
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Click for full-size image (18uc_4_med.jpg)
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Click for full-size image (18uc_5_med.jpg)
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Click for full-size image (18uc_6_med.jpg)
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Last edited by gary; 04-11-2007 at 08:42 PM.
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