Thinking About a New Scope? Think Big!




Argo Navis™ Digital Setting Circles

with Ultra Res 32K encoders

Argo Navis handpad

The Argo Navis™ Digital Telescope Computer (DTC) brings not only accurate positioning information to your telescope but also provides an enormous detailed database of tens of thousands of celestial objects. Stars, asterisms, galaxies, globular clusters, open clusters, planetary nebula, nebula, planets, asteroids, comets, earth-orbiting satellites and more.

Magnitudes, surface brightnesses, object sizes, common names, stellar classifications, stellar luminosity classes, double star separations, Hubble galaxy morphologies, constellation, detailed parameters of planets, comets, asteroids, satellites and a wealth of other information is available at your fingertips with a simple spin of the dial.

Instructions for self installation: 12.5, 15, 18, and 20 inch - 25 and 20 inch

$895.00 installed

ServoCAT Goto Drive System

Servo Drive Computerized Astronomical Telescope

ServoCAT handpad

The new full featured ServoCAT will power your Obsession telescope to new horizons - and zeniths! Now you can enjoy your Obsession telescope to it's fullest potential. Coupled with the "Argo Navis digital setting circles" your scope will be tracking with ease and provide full GoTo ability. Read the features below to learn why the ServoCAT is taking over the motorized telescope market in large aperture dobs.

The ServoCAT GoTo drive with Argo Navis digital setting circles and Ultra Res 32K encoders complete system installed is:

$2,995 on the 12.5 inch Obsession

$3,195 on the 15, 18, or 20 inch Obsessions

$3,295 on the 22 and 25 inch Obsessions


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. (Feathertouch comes standard on all UCs)



Comes standard
on all Classic Obsessions




$195 Upgrade


EV3 with Motofocus

with Motofocus

$295 Upgrade



by Starlight Instruments

$395 Upgrade

(standard on all UCs)

Ultra Res 32K resolution encoders

With mounting hardware / wiring harness only installed (you have computer already):



13mm Ethos

Ethos eyepieces by Televue

6mm, 8mm, 13mm, 17mm, and 21mm

These amazing eyepieces have a 100 degree apparent field of view. You might have to turn your head to see from one side to the other as your eyeball can't move that far!

We are often asked "What eyepieces should I use"? TeleVue eyepieces are simply the best for fast reflecting telescopes like the Obsession.

We are also a Televue dealer and offer OEM discount pricing on all eyepieces, filters, barlows and more.

Email for price and delivery info.

Barlow-Laser Collimator 2" barrel

Highly recommended. Includes 2" magnetic barlow lens and removable mask for the new barlowed laser collimating technique. Great visual aid, and no better way to accurately align fast Newtonians. Has recessed switch.

See: Collimation Instructions & Barlowed Laser Technique




with Quick Release Platform.
More details hereexternal link icon



9 x 50 finderscope

with amici prism and quick release finder rings installed


7 x 50 finder scope

13 x 80 finderscope

with amici prism and quick release finder rings installed


12 x 80 finder scope

Dew heater for secondary mirror

Dew heater

Sizes available to fit all apertures

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. 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.

See: Dew heater installation instructions


Ripstop Nylon light shroud

Ripstop Nylon light shroud

Made from 100% ripstop nylon tent fabric - not cheap cotton T-shirt fabric like most others.

Includes custom Nylon stuff sack.

$179 for 12.5" Classic

$189 for 15" Classic and 15" UC

$199 for 18" Classic and 18" UC

$209 for 20" Classic

$229 for 22" UC

$239 for 25" Classic

Counterweight kit

counterweight kit

Recommended if you intend to use heavy barlow/eyepiece combinations, a Paracorr coma corrector, a traditional finderscope, or the Argo Navis digital setting circles.


(you supply the lead shot or sand)

Introducing the English edition of Interstellarum Deep Sky Atlas

Boyd L

Everyone agrees this is the best deep sky atlas for visual observers. We are offering the waterproof field edition at 20% off the $245 cover price. For content info please see:
To order your copy please contact us at:

View sample page

Custom Obsession Telescopes decals for your trailer or vehicle

cargo trailer


Black graphic on white background with a thin black / white border, and includes your scope aperture in the lower right corner. Or get one without the scope aperture.

Made for the side walls or rear door of your scope trailer. Or apply them to the windows of your vehicle, or any surface you want to dress up with our cool looking logo.

These attractive, self adhesive decals are made of durable vinyl with a glossy vehicle overlam that will last many years.

4" x 5" $3.00 each

8" x 10" $6.00 each

14" x 18" $15.00 each

19" x 24" $25.00 each

28" x 36" $32.00 each

38" x 48" $48.00 each

48" x 60" $78.00 each

Application instructions included.

For more info, or to order,
contact Roger Greenwood at:
www.astrocrumb.comexternal link icon
(also home of the FilterSlide)

When ordering, be sure to indicate the aperture for the lower right corner. Or get them without the aperture.

third-party accessories

Hooded Observing Vest

Available from
Dark Skies Apparelexternal link icon


IZOD polo shirt

Available from
Dark Skies Apparelexternal link icon


High quality IZOD silk washed pique cotton polo shirt. It has the Obsession logo embroidered on the left chest and your telescope size & type embroidered on the left sleeve.

DSC Stalk II

Available from
Markless Astronomicsexternal link icon