Skywatcher Skyliner 250P Classic Dobsonian Telescope 254/1200 mm, borosilicate glass, Enhanced Standard Edition

Sky-Watcher Skyliner 250P Classic, 254/1200 mm Dobsonian telescope with borosilicate glass mirrors, Enhanced Standard Edition

Superb 254-mm parabolic optics, made of low-expansion borosilicate glass. Shorter cooling times thanks to outstanding thermal properties!

Further improved: A 90° 9x50 angle finder with upright image for comfortable viewing, 12.5 mm and 20 mm 70° super-wide-angle eyepieces for 96x and 60x magnification, respectively; a 1.25" adapter with a brass clamping ring to prevent damage to the eyepieces; and a universal smartphone camera adapter for taking your first photos of celestial objects. (Please note the addition of the 90° angled erect-image 9x50 finderscope differentiates this model from the standard factory version that is supplied with a straight 9x50 finder).

The Sky-Watcher Skyliner 250P Classic Dobson, with its stunning parabolic optics, provides excellent all-round performance and will deliver truly memorable views of the Moon, planets and deep-sky objects such as galaxies, nebulae and star clusters.

The experience

The Sky-Watcher Skyliner 250P Classic Dobsonian, with its stunning parabolic optics, provides excellent all-round performance and will deliver truly memorable views of the Moon & planets and deep sky objects such as galaxies, nebulae & star clusters. Skyliner Classic Dobsonians are immensely popular and perfect beginner scopes due to their high performance and simple reliable operation and are often the only telescope some users will ever need. Although the peopla at Sky-Watcher love computerised telescopes, using a star chart to find objects by hand can be far more fulfilling and will improve your knowledge of the night sky. Unplug your electronic devices, step outside, and become immersed in the wonders of the universe. It is a profoundly rewarding experience to view the treasures of the night sky through an eyepiece, in real time.

Advantages of the Dobsonian telescope

Often referred to as ´light buckets´, traditional Dobsonian telescopes provide users with the highest possible aperture for their money when compared to other telescopes of a similar size, offering an incredible aperture-to-price ratio, because most of its cost goes towards the optical tube. The Dobsonian mount, popularized by John Dobson in the 1970s, is a simple and efficient method of mounting a Newtonian reflector, based on the alt-azimuth principle. Fast & easy to set up with no time-consuming alignments, the Dobsonian mount consists of a rocker box-type mounting which allows the telescope to pivot in altitude, while the box itself is rotated on a base in azimuth. The secret of the design is to correctly balance the optical tube and use materials with low, very even which allow it to be moved easily when nudged but to stay in position when not. The mount is designed to be driven by hand as opposed to slow motion controls or by a motor.

Precision optics

The heart of any Dobsonian telescope is in the quality of its mirror optics. The accuracy of the figure, the material they are made from and the coatings applied all play an important part towards the telescope´s performance. Sky-Watcher´s prowess and reputation for commercial mirror making is well known and one of the jewels in its crown. Sky-Watcher are experts in this field and has demonstrated its unwavering ability to produce telescope mirrors of consistent high quality over decades. Parabolic (or paraboloidal) mirrors are a complex shape so need to be well made to provide the high performance expected of them. A properly figured parabolic primary mirror will eliminate spherical aberrations by bringing the light rays to the same focal point. Sky-Watcher´s diffraction-limited parabolic primary mirrors will produce sharp, contrasty images that are full of detail.

High-quality mirrors

The Skyliner 250P primary & secondary mirrors are made from special low-expansion borosilicate glass, similar to Pyrex, which has an exceptionally low coefficient of thermal expansion compared to regular glass types such as BK7 or float glass. In practice this means a quicker cool-down time to reach thermal equilibrium, without the reliance on a cooling fan, and during the cool-down process the mirrors will maintain a better shape, reducing distortions, allowing you to start observing sooner.

Both primary and secondary mirrors are finished with Sky-Watcher´s exquisite RAQ (Radiant Aluminium Quartz) coatings, which include layers of aluminium, dielectric tantalum pentoxide for enhanced reflectivity & protection and silicon dioxide, all combining for a brilliant, highly durable finish with 94% reflectivity that will last for years.

The secondary mirror is held in place by four specially designed 0.5 mm thin spider vane supports which are extremely rigid when tensioned. They serve to minimise obstruction to the light path, allowing the passage of more precious photons and keeping diffraction spikes to an absolute minimum.

The 2" focuser

The Dobsonian features a smooth-operating and precise 2" focuser with an adapter for 1.25" accessories. The draw tube features a backlash-free friction drive (Crayford), is equipped with ball bearings, and thus provides precise focusing, even with heavy eyepieces. With this focuser, you can use powerful 2" eyepieces that deliver a very bright image and a gigantic field of view. Of course, all 1.25" eyepieces can also be used.

Sturdy, practice-oriented mount

Supporting the Skyliner Classic Dobsonian is more than just a simple rocker box. The base uses special low-friction bearings for smooth, easy azimuth slewing and cleverly designed patent-protected tension control handles which ensure you always have the appropriate level of resistance for precise slewing and maximum stability. Just the right amount of tension can be intuitively applied in seconds in order to maintain perfect balance when heavy eyepieces are used, or even fully lock the vertical axis. They also conveniently double as carrying handles. An accessory tray is included to keep your accessories safe in one place. The telescope OTA can be quickly and easily separated from the base unit for convenient transportation.

Skyliner Classic Dobsonians are beautifully finished in gleaming white paint which is not just aesthetically pleasing. The white surfaces are a highly practical feature for providing more visibility, which can help prevent your expensive and carefully aligned telescope from being knocked accidentally in the dark.

- Telescope tube
- Dobsonian mount with accessory tray
- 9x50 angled finder
- 1.25" eyepieces: 70° wide-angle 12.5 mm & 20 mm
- Universal smartphone adapter (for smartphones 54 to 90 mm wide)

Safety informations: PDF Download