Skywatcher 250PDS EQ6i PRO Goto

Skywatcher Explorer 250PDS EQ6i Pro Synscan Optimised for Prime Focus Photography Fast Cool Down Time The Explorer 250PDS is a high-quality 254mm f/4.7 instrument optimised for prime-focus astrophotography as well as being a fine performer for visual use. The telescope features a high quality, internally darkened rolled steel tube of excellent rigidity. An optically matched Sky-Watcher M48 Coma Corrector (code 20233) is available separately for best astrophotography results. Supplied with a set of tube rings, 45mm dovetail bar, 28mm 2” LET eyepiece, piggyback camera adaptor and a 9x50 fully multi-coated finderscope with crosshair reticle. 1.25” & 2” eyepiece adaptors are included allowing virtually any standard 1.25” or 2” eyepiece to be used. Equipped with a 2” Dual-Speed 10:1 ratio Crayford focuser which allows coarse and very precise fine adjustments to the focusing to ensure no detail is missed. The heart of any Newtonian telescope is in the quality of its main mirror optics. The accuracy of the figure, the material they are made from and the coatings applied all play an important part. Sky-Watcher’s prowess and reputation for commercial mirror making is well known and one of the jewels in its crown. Sky-Watcher 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. The Explorer 250PDS primary and secondary mirrors are made from special Low-Expansion Borosilicate glass, similar to Pyrex. It has an exceptionally low coefficient of thermal expansion compared to regular glass types. In practice this means a quicker cool-down time to reach thermal equilibrium, and during the cool-down process the mirrors will maintain a better shape, reducing distortions, allowing you to start observing sooner. The secondary mirror is held in place by four specially designed 0.5mm 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. Both primary and secondary mirrors are finished with Sky-Watcher’s RAQ™ Radiant Aluminium Quartz coatings, which include layers of aluminium, tantalum pentoxide and silicon dioxide for a brilliant, highly durable finish with 94% reflectivity that will last for years. The colour scheme is not just an aesthetic. The OTA is tastefully finished in Sky-Watcher’s proprietary Black Diamond flecked metallic paintwork, and features, by design, complementary contrasting white painted surfaces. 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. SPECIFICATION Magnification (with eyepiece supplied) x43 Highest Practical Power (Potential) x500 Diameter of Primary Mirror 254mm Telescope Focal Length 1200mm (f/4.7) Eyepiece Supplied 28mm LET (2"/50.8mm) 1.25” and 2” Eyepiece Adaptors supplied 9x50 Finderscope in centring bracket (with crosshair reticle) 254mm Parabolic Primary Mirror (Low-Expansion Borosilicate Glass) Secondary Mirror Diameter 63mm (minor axis) Fully Collimatable Parabolic primary & secondary mirrors with Radiant™ Aluminum Quartz (RAQ™) coating providing 94% reflectivity with optimal durability and long-term performance Large, Knurled Primary Mirror Cell Collimation Knobs 2" (50.8mm) Dual-Speed 10:1 Crayford Focuser with M54 Internal Thread 0.5mm Ultra-Thin Secondary Mirror Supports Piggyback DSLR Camera Mounting Adaptor Tube weight 14.4kg 56% more Light-Gathering than 200mm EQ6i PRO Go-To Equatorial Mount with 2" Stainless Steel Tripod Supplied with Synscan Wi-Fi adaptor for control using the Synscan Pro App. The Synscan handset depicted in the product photo is an optional accessory and not included. PARABOLIC PRIMARY MIRRORS Features High Quality Parabolic Primary Mirrors to eliminate spherical aberrations inherent in 'fast' focal lengh reflectors with spherical primary mirrors. The mirrors are parabolized to bring all the light rays to the same focal point to give sharp, contrasty images, which are full of detail.