SkyWatcher Stargate-500P SynScan GoTo Truss Dobsonian Telescope, 508 mm

The SkyWatcher Stargate-500P SynScan is a computerised 508 mm Newtonian Dobsonian designed for demanding visual observing. According to the manufacturer, its 20-inch parabolic primary mirror gathers 61% more light than a 400 mm telescope. This makes it suited to observers seeking very high aperture for faint deep-sky objects and detailed views of the Moon and planets. The optical system has a 2000 mm focal length at f/4.

The primary and secondary mirrors are made from low-expansion borosilicate glass. The manufacturer says this material supports a shorter cooling time and more stable image quality while the telescope adjusts to ambient temperature. The RAQ coating is specified for reflectivity up to 94%. As with other fast f/4 Newtonian telescopes, careful collimation and adequate cooling time help the optics perform at their best.

The open truss tube can be dismantled for transport and, according to the manufacturer, assembled in about 20 minutes. The alt-azimuth GoTo mount can track automatically and locate objects from the SynScan database of more than 42,900 entries. Freedom-Find dual encoders allow manual movement without losing stored position data. This is useful when you want to point roughly by hand and then let the controller complete the positioning.

The set includes 20 mm and 12.5 mm 70-degree wide-angle eyepieces, providing 100x and 160x magnification, a 9x50 finder and a collimation eyepiece. The 2-inch Crayford focuser has a 10:1 reduction and a 1.25-inch adapter. A fabric light shroud and direct DSLR camera connection are also provided. The stated useful maximum magnification of 1016x is a manufacturer specification; actual useful magnification depends strongly on atmospheric conditions, collimation and the target.

At around 90 kg overall and shipped in four parcels, the Stargate-500P is a very large, heavy instrument rather than a grab-and-go telescope. The dismantled truss design helps transport the components, but storage, observing location and safe handling should be planned before purchase. The mount requires external power; the manufacturer states that a power supply and batteries are not included.

Specifications and features

Included in the set

• 508 mm Stargate Newtonian optical tube
• GoTo Dobsonian mount
• SynScan handset
• 2-inch Crayford focuser with 10:1 reduction and 1.25-inch adapter
• 9x50 finder
• 20 mm and 12.5 mm wide-angle eyepieces
• Collimation eyepiece
• Fabric light shroud

External power is required; batteries and a power supply are explicitly not included.