An optical telescope is a telescope which is used to gather and focus light mainly from the visible part of the electromagnetic spectrum to directly view a magnified image for making a photograph, or collecting data through electronic image sensors.
There are three primary types of optical telescope: Refractors which use lenses (dioptrics), reflectors which use mirrors (catoptrics), and catadioptric telescopes which use both lenses and mirrors in combination.
A telescope's light gathering power and ability to resolve small detail is directly related to the diameter (or aperture) of its objective (the primary lens or mirror that collects and focuses the light). The larger the objective, the more light the telescope can collect and the finer detail it can resolve.
Telescopes and binocular telescopes can be used for activities such as observational astronomy, ornithology, pilotage and reconnaissance, or watching sports or performance arts.
Other articles related to "optical, telescopes, optical telescope, telescope":
... In optical systems composed of lenses, the position, magnitude and errors of the image depend upon the refractive indices of the glass employed (see Lens (optics) and ... absence of this error is termed achromatism, and an optical system so corrected is termed achromatic ... who constructed the celebrated achromatic telescopes ...
... The sighting equipment consists of a mechanical sight and an optical telescope ... The optical telescope can be used from 100 to 600 m range with 100 m intervals ... The optical telescope is folded to the side when the weapon is transported ...
... Nearly all large research-grade astronomical telescopes are reflectors ... back down behind the primary mirror), and even external to the telescope all together (such as the Nasmyth and coudé focus) ... A new era of telescope making was inaugurated by the Multiple Mirror Telescope (MMT), with a mirror composed of six segments synthesizing a mirror of 4.5 meters diameter ...
Famous quotes containing the words telescope and/or optical:
“The telescope at one end of his beat,
And at the other end the microscope....”
—Robert Frost (18741963)
“It is said that a carpenter building a summer hotel here ... declared that one very clear day he picked out a ship coming into Portland Harbor and could distinctly see that its cargo was West Indian rum. A county historian avers that it was probably an optical delusion, the result of looking so often through a glass in common use in those days.”
—For the State of New Hampshire, U.S. public relief program (1935-1943)