15” f/4 UC
“Hi Dave, Just to let you know that my scope is a joy to use. Simple and quick setup and great views.”
- Amir A. - Negev desert, Israel
$7,495
Plus Shipping & Crating
Quick Specs:
Stacked for transport 22” x 22” x 21” high
Weight of heaviest component is 45 pounds
Eyepiece height at zenith is 59 inches
15" UC includes:
Feathertouch focuser
Telrad
Wheelbarrow handles
Counterweight kit
External light baffle
The 15" f/4 UC (Ultra Compact) is a revolutionary design. It is a large aperture telescope that collapses into a very small package. If you have limited hauling or storage capacity, (like the trunk of a small car) then this is the scope for you.
Our revolutionary Virtual Mirror Box (VMB) is the foundation of the UC design. It is a welded steel framework made from NC laser cut steel. It provides four main functions. It provides the primary mirror cell, the altitude bearings, the connection points for the truss poles, and a retainer for the wheelbarrow handles.
Now everyone can have a big aperture scope and take it to their dark sky site. This telescope will appeal to those that like the ultimate in form follows function style. Low eyepiece height means 100% of observing will be done with your feet on the ground. Or pull up a stool and enjoy some sit down observing in the lower half of the sky. The UC is all black with a modern space frame construction. If your vehicle is small or you intend to put it in the trunk, then the Ultra Compact is the obvious choice. And if you want the ultimate in Dobsonian evolution, the Obsession Ultra Compact 15" is it.
No compromises. The UC uses the same proven design criteria and materials that made the Classic Obsession so successful and the most copied larger aperture dob on the market. We use the same premium optics from Ostahowski that we do in our Classic series of telescopes.
Diffraction limited and all figured and tested with interferometry.
Ion deposition 96% enhance primary coating.
Two inch flex free glass.
One tenth wave 96% Diamond brite secondary mirror.
As with our Classic series, you cannot get better optics at any price anywhere. Ostahowski is so confident of their quality that they post the serial number and test data for ever mirror they make on their web sites for everyone to review. Nobody else does this.
"An increasing number of amateurs are driving to dark sites for visual sessions, and as always, space is at a premium. For many, that means the new Obsession UC line is just the ticket. Following on the heals of the 18" UC, Kriege and company introduced the 15" Ultra Compact in 2008. These scopes are designed to pack the most aperture into the smallest package possible, and the 15" makes it even smaller yet."
~ Tom Trusock - Cloudy Nights Reviews
“Dave,
Views are great! Gave me my best observing of the Lagoon, Orion, Helix, etc. With the increased aperture I can use filters without the image getting so faint that it's hard to see. Shorter focal length gives me wider views of open clusters, etc. than I was getting with my C11.
Easy to transport too! My wife watched me pack it into the SUV for a star party and remarked "wow, that really condenses down!
Short height means I don't need a ladder either.
I'm happy!”
Mike C.
Videos
Review of the 15" UC by Ed Ting
Review of the 15" UC (Ultra Compact) Dobsonian Telescope!
Dave Kriege gives Tom Trusock a walk-through of the Obsession 15" Ultra Compact (video courtesy of Cloudy Nights Telescope Reviews)
43% more light gathering power than a 12.5"
4X more light gathering power than an 8” Schmidt-Cassegrain
ULTRA COMPACT
15” UC in a tiny car!
“The views in the scope are great, and I love the fact that it tucks easily into my sports car, a Toyota GT-86. It was a big hit at the Bryce Canyon festival this year.”
~ Michael Carnes 15” UC - Cottonwood Heights, Utah
15" UC Specifications
Metric info shown in italics
Primary Mirror:
15" - 381 mm Ostahowski 2 inch thick mirror
Fused silica glass standard on all 15" UC primary mirrors.
96% reflectivity
Enhanced Aluminum Coating and Dielectric Overcoat (a supreme coating)
Center marked for precise collimation
plus Interferometry certification
see Optics page for more info
Secondary Mirror:
Pre-installed
2.6" - 66 mm United Lens 1/10 wave or better
Interferogram included
96% reflectivity at 550 nm
Super enhanced Brilliant-Diamond non-fading multi-dielectric coating
see Optics page for more info
Focal Length:
60" (± 2") - 1,520 mm (± 50 mm)
Eyepiece Height at Zenith:
(approximately) 59" - 150 cm
Mirror Cell:
9 point
Truss Pole:
Length: 45" (± 2") - 114 cm (± 5 cm)
Diameter: 1.25" - 32 mm
Wall Thickness: 0.035" - 0.9 mm
Upper Assembly:
Diameter: 19" - 48 cm
Height: 10" - 25 cm
Weight: 6 lbs. - 2.7 kg
Lower Assembly:
Virtual Mirror Box stacked in Rocker for Transport
22" x 22" x 21" high
Standard Features and Accessories
Feathertouch focuser by Starlight Instruments
Standard on all Ultra Compacts
Starlight Feathertouch 2 inch focuser, with 1-1/4 inch threaded adaptor for filters. Compression rings. Can be swiveled on it's base to the most convenient position. A joy to use and beautiful to look at.
Telrad
Standard on all Ultra Compacts
Upper and lower light baffles
Standard on all Ultra Compacts
Counterweight kit
Standard on all Ultra Compacts
Wheelbarrow handles
Comes standard on all Obsessions 12.5" through 25" at no extra charge.
Primary Mirror Coating
Enhanced Aluminum - 96% reflectivity, with dielectric overcoat (a supreme coating) standard on all primary mirrors. See Optics page for more info.
Secondary Mirror Coating
An Obsession exclusive - Super enhanced Brilliant-Diamond is standard on all Obsession secondary mirrors. This premium multi-dielectric coating has 96% reflectivity at 550 nm. The ultimate coating for the deep sky obsessed. This coating is standard on all Obsession secondaries at no extra charge. Brilliant-Diamond is just one of the reasons Obsessions out perform all others.
With 96% enhanced on the primary and our standard 96% Brilliant Diamond secondary, the optical system is equivalent to an extra 2" of aperture!
12 volt cooling fan
12 volt cooling fan comes standard on all Classic and Ultra Compact scopes.
Fused quartz
15” UC Obsessions use fused quartz for the primary and secondary mirror glass.
See Optics page for more info.
Optional Accessories
See the Accessories page for more info on these items
Paracorr
(Highly recommended at f/4)
$550
The Tele Vue Paracorr is a popular optical device called a coma corrector. It fixes an optical flaw called coma in fast Newtonian and Dobsonian telescopes. Coma makes stars near the edge of your view look like little comets instead of sharp points.
Ripstop Nylon light shroud
(Highly recommended)
$209 for 15" UC
$219 for 18" UC
$259 for 22" UC
Our custom fitted light shroud really fits.
Made of Ripstop Nylon
Sports an embroidered logo.
Custom nylon stuff sack with cord lock closure included.
Barlow-Laser Collimator 2" barrel
(Highly recommended)
$195
Includes 2" magnetic barlow lens and mask for the new barlowed laser collimating technique. Great visual aid and no better way to accurately align fast Newtonians. learn how
Nexus Digital Setting Circles Pro
with ultra res 32K encoders
$895
We fabricate our own steel mounting hardware and cables for the ultra res 32K res encoders. When you buy the Nexus Pro Digital Setting Circles with your Obsession you get quality factory installation. Encoder arms are easily removed with brass thumb screws. No tools required. more info
Dew heater for secondary mirror
$85
Secondary mirror heating system automatically senses the air temperature and the mirror temperature, then maintains the secondary at a preset (adjustable) temperature above the ambient air temperature to prevent dewing or icing.
Gently warms the secondary at 2-4 watts when on full. Six evenly spaced contact points for optimal thermal distribution. Uses a 9v battery (smoke alarm battery) mounted at the holder, eliminating the need for wires across the spider. No more heat ropes! On/off sensor and LED indicator included.
Sizes available to fit all apertures
Pre-installed (if ordered).
Hi Dave, Just to let you know that my scope is a joy to use. Simple and quick setup and great views. - Amir A, Negev desert, Israel
Claudio Elicer
Dave, Views are great! Gave me my best observing of the Lagoon, Orion, Helix, etc. With the increased aperture I can use filters without the image getting so faint that it's hard to see. Shorter focal length gives me wider views of open clusters, etc. than I was getting with my C11. Short height means I don't need a ladder either. I'm happy!! ~ Mike C.
Claudio Elicer Santiago Chile
Phil Chow with 15" UC in Toronto Canada
John Lynch Mount Laguna July 2015
Scott J
Roland David
Claudio Elicer, 15" UC owner in Santiago, Chile - Jan. 21, 2013
First Light at OzSky star party in Australia with Lachlan M and Richard X. OzSky is THE premier event in the Southern hemisphere. Attendees have access to ten Obsession telescopes that they can use all night for a week!
Robbin C
Gil Kedar Negev dessert Israel
Ordering Information:
A Deposit is required to place an order ($1,600 for 15" UC)
Mail the deposit to:
Obsession Telescopes
PO Box 804
Lake Mills, WI 53551
USA
You can e-mail your order, or mail it with the deposit.
With your order, please list any options and/or accessories you want, your mailing address, e-mail address if any, and phone number(s).
After we receive it, we will send you an order confirmation letter.
Delivery is usually 1 to 2 months from time of order.
Please e-mail for current delivery times.
Balance due prior to shipment.
Prices do not include shipping and crating. We ship throughout the world via UPS.
Any questions, please call or e-mail.
NOTE 10% order cancelation charge.