Editing Amateur telescope making (section)

==Telescope design==

[[File:Telescopes ameteur built.jpg|thumb|A large fork mounted telescope and several other amateur built telescopes on display at [[Stellafane]]]]
The telescopes amateur telescope makers build range from backyard variety to sophisticated instruments that make meaningful contributions to the field of [[astronomy]]. Instruments built by amateurs have been employed in planetary study, [[astrometry]], [[photometry (astronomy)|photometry]], comet and asteroid discovery to name just a few. Even the “hobbyist” end of the field can break down into several distinct categories such as: observing [[Deep-sky object|deep sky]] objects, observing the planets, solar observing, lunar observation, and [[astrophotography]] of all those classes of objects. Therefore, the design, size, and construction of the telescopes vary as well. Some amateur telescope makers build instruments that, while looking crude, are wholly suited to the purpose they are designed for. Others may strive for a more aesthetic look with high levels of mechanical “finish”. Since some amateur telescope makers do not have access to high-precision machining equipment, many elegant designs such as the [[Poncet Platform]], [[Crayford focuser]], and the [[Dobsonian telescope]] have evolved, which achieve functionality and stability without requiring precision machining.

The difficulty of construction is another factor in an amateur's choice of project. For a given design the difficulty of construction grows roughly as the square {{Citation needed|date=December 2008}} of the diameter of the objective. For example, a Newtonian telescope of {{convert|4|in|mm}} aperture is a moderately easy science fair project. A {{convert|6|to|8|in|mm|adj=on}} Newtonian is considered a good compromise size since construction is not difficult and results in an instrument that would be expensive to purchase commercially. A {{convert|12|to|16|in|mm|adj=on}} reflecting telescope is difficult, but still within the ability of the average amateur who has had experience building smaller instruments. Amateurs have constructed telescopes as large as {{convert|1|m|in}} across, but usually small groups or astronomy clubs take on such projects.
[[File:Dobson class.jpg|thumb|An amateur built [[Dobsonian]] telescope of moderate size.]]