A Dobsonian telescope is a Newtonian reflector type of telescope and is made up of an alt-azimuth mount and Sonotube. A Dobsonian telescope is a low-cost telescope that is designed to view deep sky objects. These objects need a large objective diameter combined with ability to be portable; in order to observe in non-light polluted places. Dobsonian telescopes are very popular among the amateur telescope field because of their low price and ability to observe deep-sky objects.
Features
A Dobsonian telescope uses mirrors that are made out of surplus glass ship portholes, which has a 1:16 thickness ratio. The mirrors are supported by a simple cell and use an indoor/outdoor carpet to support the weight of mirror evenly. Dobsonian telescopes have a Sonotube, which is a very durable, thick compressed paper tube. Sonotubes prevent any unwanted convection currents that get in the way of the optical light path. The Dobsonian telescope has an alt-azimuth mount, which is a two-axis mount that both supports and rotates the telescope.
Function
The Dobsonian telescope works by a mirror gathering light and focusing that light up the Sonotube. The secondary mirror reflects that focused light into the eyepiece allowing you to see images in the sky. Dobsonian telescopes collect all the light from a distant object, and are able to bring that light to a point or focus in the eyepiece. The eyepiece lens takes that bright light from the point or focus of an object and magnifies it, so that is takes up a large portion of your retina.
