• Sky-Watcher 天文望遠鏡 Dobsonians 系列 BK DOB 8" Traditional

口徑203mm,物鏡焦距1200mm,此款為牛頓式反射系統,最大特色為進光量超大,採用非球面高精度的反射鏡,鍍膜結實抗污染伸縮式主鏡,携帶搬運更加方便,具有銳利精準的解析力、體積小、倍數高,外型精美高雅,採座台式觀測,可360度旋轉機身,是專業天文觀測最佳首選機種。

The Sky-Watcher Dobsonian Telescope 203mm/1200mm (8") have 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.
DOB 8" Traditional
The Sky-Watcher Dobsonian Telescope 203mm/1200mm 8") have 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 model includes a 2" focuser with a 1.25" adapter, allowing the use of either eyepiece size. This model also includes the new feature-tension control handle.

What is Dobsonian Telescope and why the Tension Control Handle?

A simple, elegant form of an alt-azimuth mount made to carry a Newtonian reflector was popularized by John Dobson in the late 1970's. The Dobsonian mounted 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 optical tube assembly for pivoting 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 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 field of view. If there is too little friction, the telescope will not stay where it is positioned. This makes stabilizing the optical tube of the telescope difficult when using a Dobsonian mount, especially when accessories, such as a finderscope or an eyepiece, are added to the optical tube. As long as the amount of friction is at an appropriate level, and therefore stabilization of the optical tube is achieved, the 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 telescope on the Dobsonian mount currently available include a sliceable weight to counterbalance the weight of the telescope, a friction lock that must be adjusted to inhibit movement of the telescope, and a spring attached to the 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 (Patented) is to provide a 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. By providing such a tension adjuster, the 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 optical tube. Alternatively, the tension adjuster can be completely tightened to lock the optical tube in position.

品牌 Sky Watcher
型號 8吋伸縮杜普生203/1200
口徑 203mm
物鏡焦距 1200mm
目鏡 25mm,10mm
鏡筒重量 11kg
Scondary鏡直徑 47mm
焦比 F/5.9
集光力 406X
尋星鏡 8X50
目鏡焦管尺吋 2吋 含 1.25" 轉接環
管尺寸(直徑 ×長度) 205 x 112 (mm)
裝運重量 15+17 (kg)

Optical Design Newtonian (Parabolic)
Optical Diameter 203mm
Focal Length 1200mm
F/Ratio F/5.9
Secondary Mirror Diameter  47mm
Highest Practical Power 406x
Faintest Steller Magnitude 14.2
Finder Scope 8x50*
Focuser Diameter 2" with 1.25 adapter
Eyepieces 1.25" Super 25 and 10*
Tube Weight 11kg
Tube Dimensions 20.5cm x 112cm
Shipping Weight 15+17 kg
Shipping Dimensions 77x67x12 cm3; 126 x 40 x 45 cm3

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Sky-Watcher 天文望遠鏡 Dobsonians 系列 BK DOB 8" Traditional

  • 品牌: Sky-Watcher
  • 型號: BK DOB 8"
  • 庫存狀態: 有庫存
  • $16,000

  • 稅前: $16,000

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