Sky-Watcher Classic 250P

The Sky-Watcher Classic Dobsonian Telescope 254mm/1200mm (10") has a "paraboloidal" primary mirror to eliminate spherical aberration and a four-arm, secondary- mirror bracket with fine supports (0.5mm thick), to reduce diffraction spikes and light loss. In addition, this model include a 2" focuser with a 1.25" adapter, allowing the use of either eyepiece size. This model also include the new feature-tension control handle.   Optical Info Optical Design Newtonian Mirror Coatings 94% Aluminum Glass Type Borosilicate Primary Aperture (mm) 254 F/Ratio 4.7 Focal Length (mm) 1200 Secondary Diameter 64mm Secondary Obstruction (by diameter) 25% Secondary Obstruction by Area 6% Observational Info Dawes Limit 0.46 Rayleigh Limit 0.55 Limiting Mag. 14.5 Minimum Magnification 36 Maximum Magnification 500 Light Gathering (compared to next size down) 57% General Info Focuser 2" Crayford OTA Length (Retract/Ext.) 45" OTA Outer Diameter 11.37