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12.5" f/5 Classic

12.5" Classic Obsession

TONY B. - Santa Fe, New Mexico


22UC collapsed

Curved spider vanes: No diffraction spikes on stars and the ultimate in contrast for planetary work!


M13 Comparison

specs

12.5" f/5$3,695

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!


2.5 times the light gathering power of an 8 inch Schmidt-Cassegrain Obsession
12.5"
Typical
8"
Limiting stellar magnitude: 15.0 14.0
Rayleigh Resolution Limit: 0.38
arc seconds
0.68
arc seconds
Contrast limit:
(minimum diameter before a
nebular object fades from view)
6.0
arc minutes
11.0
arc minutes

Sky & Telescope review - February 2009

Sky & Telescope logo

"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."


Customer Comments

TONY B., 12.5" owner in Santa Fe, New Mexico
April 11, 2011

This little 12.5" has changed my life!  Learning all about DOBS and Obsessions and enjoying it immensely. Can't believe I've been in this hobby for decades and never had one before. For what it's worth, I've had some nice (although relatively small aperture) stuff (Mak-Newt, Mak-Cass, SCT's, Tak Mewlon, Vixen modified mak-cass, refractors, etc). I find the view through the 12.5" Classic as sweet and satisfying as ANY and better than most. THANK YOU!

Read more 12.5" customer comments


12.5" Photos

Jerry Gilliam 12.5 Classic Obsession Jerry Gilliam 12.5 Classic Obsession Jerry Gilliam 12.5 Classic Obsession Jerry Gilliam 12.5 Classic Obsession

Jerry Gilliam

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12.5" Specifications:

Metric info shown in italics


Primary Mirror:

  • 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


Secondary Mirror:

  • 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


Focal Length:

  • 63" (± 2") - 1590 mm (± 50 mm)

Eyepiece Height at Zenith:

  • (approximately) 60" - 152 cm

Mirror Cell:

  • 9-point

Truss Pole:

  • Length: 41" (± 2") - 104 cm (± 5 cm)
  • Diameter: 1" - 25 mm
  • Wall Thickness: 0.035" - 0.9 mm

Upper Assembly:

  • Diameter: 16" - 41 cm
  • Height: 10" - 25 cm
  • Weight: 5 lbs. - 2.5 kg

Lower Assembly:

  • A= 24" - 61 cm | B= 19" - 48 cm | C= 15" - 38 cm | D= 17" - 43 cm

see diagram


Mirror Box Weight:

  • (the heaviest component) 39 lbs. - 18 kg
    Weight at Handles (what you lift at Wheelbarrow handles): 7 lbs - 3 kg

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Mirror Options:

Obsessions are built with premium diffraction limited optics from Galaxy 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.

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Standard Features and Accessories:


Wheelbarrow handles

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

JMI EV3 (standard on 12.5")


JMI EV1 with motofocus

JMI EV1 with motofocus

JMI EV1

JMI EV1


Feathertouch by Starlight Instruments

Feathertouch
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!

Optional Accessories:


See the Accessories page for more info on these items


Counterweight kit

(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.


Telrad


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 super res 10K encoders

more info


ServoCAT Goto Drive System

more info


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.

more info

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Ordering Information:

A Deposit is required to place an order ($1,500 for 12.5" Classic)

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.