ICEINSPACE
Most Read Articles
Moon Phase
CURRENT MOON New Moon
0.3%
The Sun Now
Time Zones
Sydney*
11:37 pm
Perth
8:37 pm
Auckland*
1:37 am
New York
7:37 am
Paris
1:37 pm
GMT
12:37 pm




Go Back   IceInSpace > Equipment > Equipment Discussions

Reply
 
Thread Tools Rating: Thread Rating: 11 votes, 5.00 average.
  #1  
Old 04-11-2007, 04:01 PM
gary
Registered User

gary is offline
 
Join Date: Apr 2005
Location: Mt. Kuring-Gai
Posts: 3,974
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)
137.3 KB635 views
Click for full-size image (18uc_2_med.jpg)
120.4 KB605 views
Click for full-size image (18uc_3_med.jpg)
139.3 KB530 views
Click for full-size image (18uc_4_med.jpg)
143.6 KB856 views
Click for full-size image (18uc_5_med.jpg)
140.2 KB631 views
Click for full-size image (18uc_6_med.jpg)
143.3 KB501 views

Last edited by gary; 04-11-2007 at 08:42 PM.
Reply With Quote
  #2  
Old 04-11-2007, 04:04 PM
gary
Registered User

gary is offline
 
Join Date: Apr 2005
Location: Mt. Kuring-Gai
Posts: 3,974
Obsession 18 UC - photos Part 2 of 2

Here are some additional images showing the Obsession 18 UC being
assembled and finally assembled. These images were all taken by myself at
Coonabarabran October 2007.

The last image shows Dave Kriege (right) and myself (left) standing behind the
scope with its shroud on.

Best Regards

Gary Kopff
Mt. Kuring-Gai
Attached Thumbnails
Click for full-size image (18uc_7_med.jpg)
141.7 KB310 views
Click for full-size image (18uc_8_med.jpg)
142.6 KB324 views
Click for full-size image (18uc_9_med.jpg)
138.3 KB412 views
Click for full-size image (18uc_10_med.jpg)
144.0 KB424 views
Click for full-size image (18uc_11_med.jpg)
140.8 KB660 views
Click for full-size image (18uc_12_med.jpg)
138.9 KB407 views
Click for full-size image (18uc_13_med.jpg)
133.4 KB593 views

Last edited by gary; 04-11-2007 at 04:25 PM.
Reply With Quote
  #3  
Old 04-11-2007, 07:34 PM
Stephen65's Avatar
Stephen65
Registered User

Stephen65 is offline
 
Join Date: May 2007
Location: Melbourne
Posts: 358
I have a Forester, now I just need that scope.
Reply With Quote
  #4  
Old 04-11-2007, 08:12 PM
norm's Avatar
norm
Registered User

norm is offline
 
Join Date: Aug 2005
Location: Kentucky, NSW
Posts: 772
Great write-up Gary.

Certainly can see a niche for this type of scope. Was there any noticable coma being f4.2 and how was it for collimation?

Cheers, Norm
Reply With Quote
  #5  
Old 04-11-2007, 08:20 PM
gary
Registered User

gary is offline
 
Join Date: Apr 2005
Location: Mt. Kuring-Gai
Posts: 3,974
Quote:
Originally Posted by norm View Post
Great write-up Gary.

Certainly can see a niche for this type of scope. Was there any noticable coma being f4.2 and how was it for collimation?

Cheers, Norm
Hi Norm,

Dave recommends a Paracorr at this short a focal length.

Apparently the collimation is just as easy to do on the UC as it is on the classic.
Obsession ship the mirrors with a center mark to assist. Optically, it was brilliant.

Best Regards

Gary Kopff
Mt. Kuring-Gai

Last edited by gary; 04-11-2007 at 08:38 PM.
Reply With Quote
  #6  
Old 04-11-2007, 08:35 PM
gary
Registered User

gary is offline
 
Join Date: Apr 2005
Location: Mt. Kuring-Gai
Posts: 3,974
Quote:
Originally Posted by Stephen65 View Post
I have a Forester, now I just need that scope.
Hi Stephen,

It certainly looked sweet in the back of mine.

As I mentioned, you can fit it easily into the back cargo area with the rear seats
still available for passengers. You get a lot of aperture for the number of
cubic cm the UC occupies when in its compact transportation state.

I suspect there are a lot of enthusiasts out there that would love to buy that
telescope they always wanted but aren't in a hurry to buy a new vehicle to
transport it in. You don't need a station wagon or trailer for this thing, just
about any car will do, even most small ones.

For some, this opens up the opportunity for observing to become a family
experience. With the rear seats free, there is space for the kids.

Best Regards

Gary Kopff
Reply With Quote
  #7  
Old 04-11-2007, 09:28 PM
coldspace's Avatar
coldspace
Registered User

coldspace is offline
 
Join Date: May 2007
Location: Brisbane
Posts: 505
Hi Gary,

Any idea on pricing for this beauty.

Matt
Reply With Quote
  #8  
Old 04-11-2007, 10:53 PM
gary
Registered User

gary is offline
 
Join Date: Apr 2005
Location: Mt. Kuring-Gai
Posts: 3,974
Quote:
Originally Posted by coldspace View Post
Hi Gary,

Any idea on pricing for this beauty.

Matt
Hi Matt,

Apparently they are priced the same as the classic 18" with the same items.
Obsession have some US Dollar pricing on their web site here -
http://www.obsessiontelescopes.com/t..._UC/index.html

Best Regards

Gary Kopff
Mt. Kuring-Gai
Reply With Quote
  #9  
Old 05-11-2007, 03:54 PM
fringe_dweller's Avatar
fringe_dweller
on the highway to Hell

fringe_dweller is offline
 
Join Date: May 2005
Location: Adelaide
Posts: 2,623
wow nice Gary! also love the extremely photogenic location and weather! and great photos, drooool! cheers!
Reply With Quote
  #10  
Old 07-11-2007, 10:19 AM
Roger Davis's Avatar
Roger Davis
Registered User

Roger Davis is offline
 
Join Date: Nov 2004
Location: Sydney
Posts: 292
Geez Gary, Do you know how many owners of Foresters there are in my club alone? Let me think, gee just in the Instrument Making Section there are four of us! and that's a group of about 20. Extrapolating that's 180 members with Foresters! What has Dave done??! Looks like I'm having words with him!!
Reply With Quote
  #11  
Old 07-11-2007, 10:33 AM
gary
Registered User

gary is offline
 
Join Date: Apr 2005
Location: Mt. Kuring-Gai
Posts: 3,974
Quote:
Originally Posted by fringe_dweller View Post
wow nice Gary! also love the extremely photogenic location and weather! and great photos, drooool! cheers!
Hi Fringe_dweller,

Thank you! I appreciate your kind comments.

Best regards

Gary
Reply With Quote
  #12  
Old 07-11-2007, 10:56 AM
gary
Registered User

gary is offline
 
Join Date: Apr 2005
Location: Mt. Kuring-Gai
Posts: 3,974
Quote:
Originally Posted by Roger Davis View Post
Geez Gary, Do you know how many owners of Foresters there are in my club alone? Let me think, gee just in the Instrument Making Section there are four of us! and that's a group of about 20. Extrapolating that's 180 members with Foresters! What has Dave done??! Looks like I'm having words with him!!
Hi Rog,

Love the extrapolation!

I bet we all did the same thing. You are down at the Subaru dealership
(there's an astronomical connection right away of course, with Subaru being
the Japanese name for The Pleiades), you open up the hatch at the back
and the first thing that enters your head is imagining a telescope of some
sort being in there.

I even had a US enthusiast email me yesterday, having read this thread on
IceInSpace, asking my opinion of the Forester as an astro-transportation
vehicle. (Hello Mark!).

With light, sweet crude heading toward US$100 a barrel, I am sure down-sizing
of vehicles is a consideration for an increasing number of Americans. DaveK,
being the astute businessman he is, has undoubtedly seen this coming, so the
Ultra Compact is very much a product introduction with impecable timing.

Best Regards

Gary
Reply With Quote
  #13  
Old 07-11-2007, 05:40 PM
Blue Skies's Avatar
Blue Skies (Jacquie)
It's about time

Blue Skies is offline
 
Join Date: Nov 2005
Location: Melbourne
Posts: 1,171
This new ultralight model has certainly got me salivating. I don't have a subaru but I was certainly thinking big scopes when I got my early model Honda CR-V with heaps of room in the back! A friend here bought a 15" Obsession a year or so ago and I finally got to look through it recently under dark skies and was very impressed - it was outdoing the club 17.5" with Coulter mirror that has a damaged surface. The compact size is definitely a drawcard, as well as it being transported in only two 'packages', that makes less to forget when packing the car.
Reply With Quote
  #14  
Old 08-11-2007, 06:38 PM
gary
Registered User

gary is offline
 
Join Date: Apr 2005
Location: Mt. Kuring-Gai
Posts: 3,974
New Obsession DVD features 18 UC

Quote:
Originally Posted by Blue Skies View Post
This new ultralight model has certainly got me salivating.
... The compact size is definitely a drawcard, as well as it being transported in only two 'packages', that makes less to forget when packing the car.
Hi Blue Skies,

You might like to request a copy of the latest Obsession DVD. I received
a copy today from Dave Kriege and it includes a new segment on the 18
Ultra Compact that was video'd at Coonabarabran. You get to see Dave
assemble and disassemble the scope and he talks about its various attributes.

The DVD is free and Dave will post it to anywhere in the world for free as well.
See here for details - http://www.obsessiontelescopes.com/contact/index.html

Best Regards

Gary Kopff
Mt. Kuring-Gai

Last edited by gary; 08-11-2007 at 09:14 PM.
Reply With Quote
  #15  
Old 08-11-2007, 08:34 PM
Omaroo's Avatar
Omaroo (Chris Malikoff)
Let there be night...

Omaroo is offline
 
Join Date: Aug 2006
Location: Sydney/Cooma
Posts: 7,628
One word - "beautiful"
Reply With Quote
  #16  
Old 09-11-2007, 09:20 AM
GrahamL's Avatar
GrahamL
pro lumen

GrahamL is offline
 
Join Date: Jun 2006
Location: Wollongbar
Posts: 2,748
very nice gary.. any noticable bump when the alt bearing moves
over the folding joint ?
Reply With Quote
  #17  
Old 10-11-2007, 01:18 PM
gary
Registered User

gary is offline
 
Join Date: Apr 2005
Location: Mt. Kuring-Gai
Posts: 3,974
Quote:
Originally Posted by nightstalker View Post
very nice gary.. any noticable bump when the alt bearing moves over the folding joint ?
Hi Graham,

Thanks for the post.

Dave is proud of the fact that he came up with a clever way to eliminate the bump
completely, so there is no bump.

Best Regards

Gary Kopff
Mt. Kuring-Gai
Reply With Quote
  #18  
Old 11-11-2007, 12:40 PM
tnott's Avatar
tnott
Oblonnygox

tnott is offline
 
Join Date: Aug 2006
Location: Adelaide
Posts: 221
Looks great. Similar ideas to many of the newer ATM scopes out there at the moment. I'm interested that he managed to eliminate the bump where the bearing folds over. In the Tridob design I copied for my 16" scope this is accomplished by having three fins, with the front two folding over the mirror box, but it requires extra bits of teflon as keepers on the sides. http://www.iceinspace.com.au/index.p...63,324,0,0,1,0


Can't see the point of the shroud to be honest, as most stray light gets in around the top end around the focuser and secondary assembly, and this is above the shroud in this design. Also, light is not blocked from getting into the light path around the primary either. Might be more to do with customer perceptions than blocking stray light. personally, I'd be baffling the focuser and using a bigger baffle behind the secondary instead.

Tim.
Reply With Quote
  #19  
Old 11-11-2007, 12:59 PM
janoskiss's Avatar
janoskiss (Steve H)
Registered User

janoskiss is offline
 
Join Date: Jan 2005
Location: Clifton Hill, VIC
Posts: 5,539
Quote:
Originally Posted by tnott View Post
Can't see the point of the shroud to be honest, as most stray light gets in around the top end ...
Main reason to have one, and it's a good one, is to help keep dew off the primary.
Reply With Quote
  #20  
Old 11-11-2007, 01:09 PM
tnott's Avatar
tnott
Oblonnygox

tnott is offline
 
Join Date: Aug 2006
Location: Adelaide
Posts: 221
Quote:
Originally Posted by janoskiss View Post
Main reason to have one, and it's a good one, is to help keep dew off the primary.
Haven't ever heard of this happening to a thick 18" primary. My 16'' has never, ever dewed up. In fact I am pretty sure that cooling that much thermal mass is more of a problem. Michele Plettstone maintains that a shroud makes little or no difference with dew formation.

But it would keep keys or coke off the primary.
Reply With Quote
Reply

Bookmarks

Thread Tools
Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +10. The time is now 10:37 PM.

Powered by vBulletin Version 3.8.7 | Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Advertisement
FLI Cameras and Imaging Accessories
Advertisement
Night Sky Secrets
Advertisement
Bintel
Advertisement
AS&T November/December 2014
Advertisement
ZWO Cameras at Optics Central
Advertisement
Astronomy Alive
Advertisement
OzScopes Authorised Dealer
Advertisement
Astronomy and Electronics Centre
Advertisement
Advertisement
10x IceInSpace Stickers