Sky-Watcher Dobson 8" sliding telescope

Sky-Watcher is a world leader in the field of telescope manufacturing, especially Dobson-mounted Newtons. For years, the company has paid special attention to the highest quality optics used in its telescopes, which is reflected in the most beautiful images of the Universe and in many positive reviews around the world. With a wealth of experience dating back to 1990, Sky-Watcher brand Dobsons are produced in the most elegant, mature and classic form, which is the most economical and affordable. Although there are many imitators on the market, no one equals Sky-Watcher in the ability to create not only optically excellent, but also affordable Dobson telescopes.

A large Newtonian system telescope suspended on a Dobson mount with a diameter of 20cm. Due to its significant optical capabilities and relatively low price, this telescope is a great option for beginners yet demanding astronomy enthusiasts.

The 20cm diameter mirror and moderate light intensity make this telescope suitable both for observing real details on the planets of the solar system and under dark skies it will allow to find hundreds of objects such as clusters and galaxies. This telescope requires no power supply, is very easy to use and always ready to use.

Optical system The telescope is designed in the classical Newtonian system. The main mirror of the telescope has a parabolic shape, a diameter of 200mm and a focal length of 1200mm. The optical intensity of the telescope is f/6, which is a fairly optimal value at which no strong coma phenomenon is observed at the edges of the image. Telescopes of this type are less burdened with features that are considered to be disadvantages of Newtonian telescopes. Relatively small coma, moderate secondary obstruction makes images from 8-inch dobsonians quite sharp and the telescope gives not only good images of nebular objects, but also rich in detail images of planets.

The extendable design of the Sky-Watcher Construction is unique on the market - large Dobsonian telescopes can be folded for storage so they take up much less space. Folding is done thanks to pull-out elements of the tube, no tools are required here, nor is it necessary to disassemble the tube into separate elements. The telescope is ready for observation within seconds. The precision-made mechanism means no need for collimation each time after disassembly.

Pyrex mirror All Sky-Watcher Dobson 8" and larger telescopes come standard with a mirror made of PYREX, a glass with low thermal expansion, so the image quality given by a telescope with such a mirror is higher than that of telescopes with a mirror made of ordinary glass.

Mounting The telescope is suspended on an azimuthal Dobson mount. The Dobson mount is a simple and very stable design that allows the telescope to be easily rotated in azimuth and elevation. The telescope is mounted on two sides in a forked mount, while the entire top of the mount rotates at the base. The telescope's very low center of gravity and its construction with fairly rigid materials makes it hang much more stable than parallactic mounts.

Extractor The telescope is equipped with a 2" eyepiece extractor with a reduction to 1.25". It is a Crayford focuser, operating smoothly and without backlash. It comes with an extension for 2", extension/reduction for 1.25". The extensions should be used interchangeably without combining them into one set. The focuser is compatible with autofocus drives manufactured by Sky-Watcher.

Astronomical Observations

• Solar System: objects on the lunar surface larger than 1 km; sunspots and their structure, the granulation of the photosphere clearly visible; all planets of the Solar System; phases of Mercury and Venus the disk of Mars, polar caps during periods of opposition, the first details of the surface visible clear several zones of Jupiter's belts and Galilean moons Saturn's rings with the Cassini gap, belts in the atmosphere and several smaller moons of the planets Uranus and Neptune visible as stars with a clear blue tint movement of many asteroids against the background of stars observations of many faint comets, visible structure of comets.
• Stars approx: 2.7 million stars across the sky, with brightness up to about 12.5-13 magnitude double and multiple stars angularly separated by more than 0.7-0.8". colors of many stars.
• Nebular objects: All objects of the Messier catalog dozens or even hundreds of globular clusters, in many cases broken into individual stars hundreds of open clusters with many visible differences in structure dozens of nebulae, including the first details, rich and subtle details of bright nebulae dozens of galaxies with visible details of structures, clear shapes and angular position of disks visible structure and structure of many planetary nebulae, increase in contrast with nebula filters visible supernova remnants.

Due to the increase in the diameter of the telescope's mirror to a diameter of 20cm, objects are seen much more clearly and details present themselves in a more obvious way than with telescopes with diameters of 130 or 150mm. For this reason, the image seen in such a large telescope becomes susceptible to the effects of artificial light illumination of the sky, air pollution and atmospheric stability (seeing), as well as the accuracy of the collimation of the optics. Please keep these limitations in mind and take them into account for optimal sky images with telescopes 20cm and larger.

Ground observations A telescope with this type of optics is not quite suitable for ground observations. To invert the image, you need to use a so-called straightening lens, which will reverse the image to a natural (straight) one. Together with the straightening lens and the mount on which it was placed, it can be used as a simple instrument for ground observations. Since the Dobson mount makes it easy to control the telescope in the vertical and horizontal axes and has high rigidity and reduces all vibrations, it becomes possible to observe aircraft at cruising altitudes.

Technical data

• Product ID 71010
• Sky-Watcher brand
• Warranty, years 2
• EAN 2400000032489
• Shipping weight, kg 0
• PCN 9005800000
• Optical design reflector
• Type Newtonian telescope
• Objective lens diameter (aperture), mm 203.0
• Focal length, mm 1200
• Aperture number f/5.9
• Resolution threshold in angular seconds 0.58
• Stellar magnitude limit 14.2
• Dobsonian mount, elevation-azimuthal
• Mount weight, kg 12
• Tube dimensions, mm (830 - 1120)x230
• Mass of the tube, kg 11
• Beginner level, experienced users
• Objects observed Solar System planets and deep sky objects