Despite its rather small size the Questar is a truly superior telescope. Its optics are of the highest quality and are specially coated to minimize light loss due to reflections. The outside of the barrel is fitted with an enameled star chart which can slide up to serve as a dew cap or slide off, exposing a lunar map. The gearing is smooth and effortless and an internal motor provides accurate tracking while observing. The telescope itself is a Maksutov-Cassegrain type.
Light enters the telescope passing through a correcting lens to the spherical primary mirror.
The light then passes back to the front where a secondary mirror reflects it back down through an opening in the primary mirror to a prism which redirects the light to the eyepiece.