Sky watcher skyliner 150p classic 153mm 6 f1200 parabolic dobsonian telescope these instruments offer an incredible aperture to price ratio the dobsonian mount popularized by john dobson in the late 1970s is a very simple but effective method of mounting a newtonian reflector based on the alt azimuth principle fast and easy to set up the dobsonian mount consists of a box type mounting which allows the telescope to pivot in altitude while the box itself is rotated on a base in azimut