Concept
Optical telescope
Related concepts (48)
Schmidt camera
A Schmidt camera, also referred to as the Schmidt telescope, is a catadioptric astrophotographic telescope designed to provide wide fields of view with limited aberrations. The design was invented by Bernhard Schmidt in 1930. Some notable examples are the Samuel Oschin telescope (formerly Palomar Schmidt), the UK Schmidt Telescope and the ESO Schmidt; these provided the major source of all-sky photographic imaging from 1950 until 2000, when electronic detectors took over. A recent example is the Kepler space telescope exoplanet finder.
Newtonian telescope
The Newtonian telescope, also called the Newtonian reflector or just a Newtonian, is a type of reflecting telescope invented by the English scientist Sir Isaac Newton, using a concave primary mirror and a flat diagonal secondary mirror. Newton's first reflecting telescope was completed in 1668 and is the earliest known functional reflecting telescope. The Newtonian telescope's simple design has made it very popular with amateur telescope makers.
Dioptrics
Dioptrics is the branch of optics dealing with refraction, similarly the branch dealing with mirrors is known as catoptrics. Dioptrics is the study of the refraction of light, especially by lenses. Telescopes that create their image with an objective that is a convex lens (refractors) are said to be "dioptric" telescopes. An early study of dioptrics was conducted by Ptolemy in relationship to the human eye as well as refraction in media such as water.
Airglow
Airglow (also called nightglow) is a faint emission of light by a planetary atmosphere. In the case of Earth's atmosphere, this optical phenomenon causes the night sky never to be completely dark, even after the effects of starlight and diffused sunlight from the far side are removed. This phenomenon originates with self-illuminated gases and has no relationship with Earth's magnetism or sunspot activity. The airglow phenomenon was first identified in 1868 by Swedish physicist Anders Ångström.
Atmospheric refraction
Atmospheric refraction is the deviation of light or other electromagnetic wave from a straight line as it passes through the atmosphere due to the variation in air density as a function of height. This refraction is due to the velocity of light through air decreasing (the refractive index increases) with increased density. Atmospheric refraction near the ground produces mirages. Such refraction can also raise or lower, or stretch or shorten, the images of distant objects without involving mirages.
Long-focus lens
In photography, a long-focus lens is a camera lens which has a focal length that is longer than the diagonal measure of the film or sensor that receives its image. It is used to make distant objects appear magnified with magnification increasing as longer focal length lenses are used. A long-focus lens is one of three basic photographic lens types classified by relative focal length, the other two being a normal lens and a wide-angle lens.
Magnifying glass
A magnifying glass is a convex lens that is used to produce a magnified of an object. The lens is usually mounted in a frame with a handle. A magnifying glass can be used to focus light, such as to concentrate the sun's radiation to create a hot spot at the focus for fire starting. A sheet magnifier consists of many very narrow concentric ring-shaped lenses, such that the combination acts as a single lens but is much thinner. This arrangement is known as a Fresnel lens.
Very Large Telescope
The Very Large Telescope (VLT) is a facility operated by the European Southern Observatory, located on Cerro Paranal in the Atacama Desert of northern Chile. It consists of four individual telescopes, each equipped with a primary mirror that measures 8.2 meters in diameter. These optical telescopes, named Antu, Kueyen, Melipal, and Yepun (all words for astronomical objects in the Mapuche language), are generally used separately but can be combined to achieve a very high angular resolution.
Aperture synthesis
Aperture synthesis or synthesis imaging is a type of interferometry that mixes signals from a collection of telescopes to produce images having the same angular resolution as an instrument the size of the entire collection. At each separation and orientation, the lobe-pattern of the interferometer produces an output which is one component of the Fourier transform of the spatial distribution of the brightness of the observed object. The image (or "map") of the source is produced from these measurements.
Photographic plate
Photographic plates preceded photographic film as a capture medium in photography, and were still used in some communities up until the late 20th century. The light-sensitive emulsion of silver salts was coated on a glass plate, typically thinner than common window glass. Glass plates were far superior to film for research-quality imaging because they were stable and less likely to bend or distort, especially in large-format frames for wide-field imaging. Early plates used the wet collodion process.