Thinking About a New Scope? Think Big!
12.5" f/5 Classic
- 12.5" Specifications
- Mirror Options
- Standard Features and Accessories
- Optional Accessories
- Ordering Information
James Book, in Ottawa, Ontario Canada with his 11 year old 12.5" Obsession - purchased October 2004.
Curved spider vanes: No diffraction spikes on stars and the ultimate in contrast for planetary work!
Plus Shipping & Crating
The Obsession 12.5 f/5 is a premium telescope for observers that want the best of all worlds.
Medium Aperture, fantastic f/5 images, no diffraction spikes!
- Crisp images at f/5 so no coma corrector needed.
- Super compact size that can be hauled in any car.
- Full thickness primary for perfect images.
- Curved spider vanes for views like an apochromat and no diffraction spikes.
- Fully compatible with the powerful Argo Navis digital setting circles.
- Nearly everyone can observe with their feet on the ground! In fact sit down astronomy is possible for nearly half the sky. Ideal for star parties, public viewing events, schools or anyone that wants a premium telescope.
- Views better than anything on the market of similar aperture. Best of all it's an Obsession with our famous quality and design at a fantastic price.
- Wheelbarrow handles included at no extra charge.
- Ease of use second to none.
- Fast set up with no ladder needed.
|2.5 times the light gathering power of an 8 inch Schmidt-Cassegrain||Obsession
|Limiting stellar magnitude:||15.0||14.0|
|Rayleigh Resolution Limit:||0.38
(minimum diameter before a
nebular object fades from view)
Sky & Telescope review - February 2009
"Portability is definitely one of the 12.5 inch Obsession's biggest assets. The instrument is remarkably rigid. The optics in the Obsession really delivered. The views were remarkably crisp and bright. Star test showed the primary mirror (made by Optical Mechanic Inc.) to be first rate. The scope has a curved-vane secondary mirror support which means that bright stars are free of diffraction spikes, something I find quite appealing. The bottom line is that the 12.5 inch Obsession is a ruggedly built, portable scope that should delivery first-rate views for a lifetime."
Ken M., 12.5" owner in Eugene, Oregon
December 28, 2015
Hi Dave, This photo was taken last summer at Golden State Star Party in northern California and shows the scope with Telrad and Argo Navis mounted on it.
Now that I've had the scope for a little over two years I've come to really appreciate the wonderful views and the incredible smooth motion of the scope. Thanks again for creating such a great product.
Best to you in 2016,
Metric info shown in italics
- 12.5" - 317 mm OMI 2 inch thick mirror
- 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
- 2.14" - 54 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
- 63" (± 2") - 1590 mm (± 50 mm)
Eyepiece Height at Zenith:
- (approximately) 60" - 152 cm
- Length: 41" (± 2") - 104 cm (± 5 cm)
- Diameter: 1" - 25 mm
- Wall Thickness: 0.035" - 0.9 mm
- Diameter: 16" - 41 cm
- Height: 10" - 25 cm
- Weight: 5 lbs. - 2.5 kg
- A= 24" - 61 cm | B= 19" - 48 cm | C= 15" - 38 cm | D= 17" - 43 cm
Mirror Box Weight:
- (the heaviest component) 39 lbs. - 18 kg
Weight at Handles (what you lift at Wheelbarrow handles): 7 lbs - 3 kg
Obsessions are built with premium diffraction limited optics from Ostahowski and OMI (Optical Mechanics Inc.). See Optics page for more info.
Only OMI supplies mirrors for our 12.5".
Interferometry certification included on all mirrors, both primary and secondary. Ion deposition 96% enhanced coatings standard on all mirrors.
Standard Features and Accessories:
Standard on all Obsessions 12.5" through 25" at no extra charge.
Choose from four great focusers
The JMI EV3 comes standard on all Classic Obsessions. Or upgrade to the EV1, or EV1 with motofocus, or the awesome Feathertouch by Starlight Instruments. See the Focuser Options page for more information.
JMI EV3 (standard on 12.5")
JMI EV1 with motofocus
by Starlight Instruments
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.
See the Accessories page for more info on these items
(you supply the lead shot or sand) Recommended if you intend to use heavy barlow/eyepiece combinations, a Paracorr coma corrector, a traditional finderscope, or the Argo Navis digital setting circles.
Ripstop Nylon light shroud
Barlow-Laser Collimator 2" barrel
(Highly recommended). 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
Argo Navis digital setting circles
with ultra res 32K encoders
ServoCAT Goto Drive System
Dew heater for secondary mirror
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.
Pre-installed (if ordered).
A Deposit is required to place an order ($1,500 for 12.5" Classic)
Mail the deposit to:
PO Box 804
Lake Mills, WI 53551
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.