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Sky-Watcher 8" Traditional Dobsonian Telescope - 31020

Sky-Watcher   ——   SKU: SKY-31020
old price $528.00 – 10% savings
$470.00 CAD
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About the Sky-Watcher 8" Traditional Dobsonian Telescope...

The Sky-Watcher Dobsonian Telescope 203mm/1200mm (8") has a "paraboloidal" primary mirror to eliminate spherical aberration and a four-arm, secondary- mirror bracket with fine supports (0.5mm thick), to reduce diffraction spikes and light loss. In addition, this Sky-Watcher Telescope includes a 2" focuser with a 1.25" adapter, allowing the use of either eyepiece size. This Sky-Watcher Telescope also includes the new feature-tension control handle.

 

What is Dobsonian Telescope and why the Tension Control Handle? It''s a simple, elegant form of an alt-azimuth mount made to carry a Newtonian reflector and was popularized by John Dobson in the late 1970''s. The Dobsonian mounted telescope, like the Sky-Watcher 8" Traditional Dobsonian Telescope is popular among amateur astronomers and telescope makers because of its simplicity. In its simplest form, the Dobsonian mount consists of a box which allows the Sky-Watcher Telescope optical tube assembly to pivot in altitude, while the box itself is swiveled on a base in azimuth.

 

The Dobsonian mount usually relies on the friction between the side bearings on the optical tube of the Sky-Watcher Telescope and a frictional material on the saddle to hold the optical tube in place. If there is too much friction, the telescope is difficult to move to center an object in the filed of view. If there is too little friction, the telescope will not sty where it is positioned. This makes stabilizing the optical tube of the telescope difficult when using a Dobsonian mount, especially when Sky-Watcher Accessories, such as a finderscope or an Sky-Watcher Telescope Eyepieces, are added to the optical tube. As long as the amount of friction is at an appropriate level, and therefore stabilization of the Sky-Watcher Telescope optical tube is achieved, the Sky-Watcher 8" Traditional Dobsonian Telescope can remain in its desired position to view an object and maintain its position even when the mount is rotated.

 

The devices for stabilizing a Sky-Watcher Telescope on the Dobsonian mount currently available include: a sliceable weight to counter balance the weight of the telescope, a friction lock that must be adjusted to inhibit movement of the telescope, and a spring attached between the Sky-Watcher Telescope tube and mount to aid in stabilization. These devices are inconvenient to use because they do not provide a simple and user-friendly way to adjust the friction.

 

The object of the Sky-Watcher Tension Control Handle invention (US Patent No. 6,940,642) is to provide a tension adjuster that users can easily turn to add or reduce tension, thereby increasing or decreasing the friction between the Sky-Watcher Telescope optical tube and the sideboard of the mount. By providing such a tension adjuster, the Sky-Watcher 8" Traditional Dobsonian Telescope does not need to be balanced in order to stay in position. The tension adjuster can be tightened such that the optical tube can stay in a position but can still be moved when prompted to adjust the position of the Sky-Watcher Telescope optical tube. Alternatively, the tension adjuster can be completely tightened to lock the optical tube in position.

 

Don''t forget, we carry plenty of Sky-Watcher Accessories, too! Look for Sky-Watcher Telescope Eyepieces and Sky-Watcher Telescope Filters for visual observers!

 

 

Sky-Watcher 8" Traditional Dobsonian Telescope Features...

 

  • A "paraboloidal" primary mirror to eliminate spherical aberration and a four-arm, secondary- mirror bracket with fine supports (0.5mm thick), to reduce diffraction spikes and light loss

     

     

  • 2" focuser with a 1.25" adapter, allowing the use of either eyepiece size

     

     

  • Tension adjuster that users can easily turn to add or reduce tension, thereby increasing or decreasing the friction between the optical tube and the sideboard of the mount

     

     

  • Tension adjuster can be completely tightened to lock the optical tube in position

     

     

  • The Dobsonian mount consists of a box which allows the optical tube assembly to pivot in altitude, while the box itself is swiveled on a base in azimuth

     

     

  • The telescope can remain in its desired position to view an object and maintain its position even when the mount is rotated

 

Sky-Watcher 8" Traditional Dobsonian Telescope Specifications...

Optical Design: Newtonian Reflector (Parabolic)

Lens/Mirror Material: Pyrex

Diameter: 203mm

Focal Length: 1200mm

Scondary Mirror Diameter: 47mm

F/ratio: F/5.9

Highest Practical Power: 406x

Faintest Steller Magnitude: 14.2

Resoving Power: 0.58

Finderscope: 9X50

Focuser diameter: 2" with 1.25" adapter

Diagonal: n/a

Eyepiece(s): 1.25" Super 25 and 10

Mount Type: Dobsonian

Slow-motion Control: n/a

Counterweight(s): n/a

Piggyback Bracket: No

Accessory Tray: Eyepiece Rack

Ground Board Diameter: 52cm

Ground Board Weight(s): n/a

Motor Drive: No

Go-to: No

Tube Weight: 11kgs

SkyWatcher Product Number: 31020