Dobsonian Telescope

A conventional Newtonian reflector optical tube on an inexpensive
plywood or fiberboard altazimuth mount. Nylon or Teflon bearings allow
smooth telescope motion at a finger's touch, with no vibration or
unsteadiness. The scope is moved by hand from object to object (there
are no manual slow motion controls or motor drives) using a technique
called star-hopping to locate objects. Usually it's a large aperture,
fast focal ratio scope designed for visual deep space observing -
although 6" and 8" medium f/ratio Dobsonians also suitable for planetary
observing are becoming increasingly popular. Cannot be used for
astrophotography. The Dobsonian is an economical way to get into large
aperture astronomy at a fraction of the cost of an equatorially-mounted
scope.