Catadioptric telescope aperture 150 mm focal length 1 500 mm focal ratio 110 optical system schmidt cassegrain suitable for beginners enthusiasts max useful magnification 300 x tracking altazimuth mount azimutal goto nexstar 68 se tripod steel tripod features starpointer telescope features astrophotography suitable easily transportable astrophotography function digiscoping lens barrel length 340 mm minimum useful magnification 21 coating starbr