Newton 200/800 Black Diamond Dual Speed ​​OTA Telescope

• Unique, versatile optical tube for visual observation and astrophotography.
• Ideal for planetary and deep sky observation (galaxies, nebulae)
• Includes Crayford Linear Power focuser, 10:1 ratio (best sharpness setting)
• Oriented for astrophotography with f/d ratio of 4

For astrophotographers, in order to offer better performance in deep sky images, Sky-Watcher has reduced the focal length of the "classic" Black Diamond range to f/4 to offer a wider field and significantly faster photographic speed (2 times between two instruments). at f/4 and f/5). For the same exposure time, a shorter focal length ratio allows more signal to be obtained or an equivalent signal to reduce the exposure time. In addition, the size of the tube is reduced, which also means less wind resistance.

Its Newton design offers several advantages over other families of instruments (Cassegrain glasses and telescopes). Mirrors are cheaper to manufacture for the same diameter and their focal ratio is generally very low. In this way you will be able to benefit, for an attractive price, from a bright telescope that offers a very wide field of observation (in this case f/D=4) . The central obstruction is also weaker than that of Cassegrain-type telescopes.

The model with a 200 mm primary mirror is one of the large diameter amateur instruments capable of revealing many deep sky objects and details about the planets and the Moon. In fact, it captures 78% more light than a 150mm telescope and promises years of observations full of discoveries for both beginners and amateur astronomers.

Unlike very cheaply made or small diameter Newton telescopes, the 150, 200, 254 and 300 mm Newton Sky-Watchers have a parabolic primary mirror . The mirrors are polished spherically and then trimmed to achieve a parabolic shape (more expensive and difficult to obtain). This is an essential selection criterion for instruments larger than 130 mm and with short f/D .

Focusing is achieved using a dual-flow Crayford eyepiece. It allows you to obtain fine focus thanks to the 1:10 reduction . A very noticeable advantage during observations with high magnifications and when taking images. Can support heavy loads (e.g. APN) . A 31.75mm adapter is supplied as standard to use eyepieces of the same format from the 50.8mm output. An adjustment screw located at the bottom of the eyepiece holder allows you to maintain focus by following the orientation of the optical tube.

To present as little obstruction as possible, the secondary (flat) mirror mounting bracket has 4 thin branches , with a width of 0.5 mm. Being sufficiently rigid, they limit diffraction peaks in bright stars and excessive luminosity loss. A 9x50 achromatic finderscope on its support is also supplied as standard.

Specifications

Items delivered

• 1 Sky-Watcher 200mm f/4 optical tube
• 1 Crayford Linear Power 50.8mm Sky-Watcher focuser with microfocuser (dual speed 1:10) and 31.75mm adapter
• 1 reinforced dovetail type Vixen
• 2 fixing collars
• 1 Piggyback mount for Kodak camera on top of one of the mounting clamps
• 1 straight finder 9x50

Astrophotography in the product image: The Lagoon Nebula (M8) by Vincent Duchêne (Cannes, France). 12-hour exposure with a Sky-Watcher Newton 200mm f/4 telescope and a ZWO ASI1600MM-Pro camera. Sky-Watcher NEQ6 Pro-GoTo equatorial mount, 31.75mm 5-position ZWO filter wheel and Baader 31.75mm LRGB, 7nm H-Alpha filters.