The history of the telescope can be traced to before the invention of the earliest known telescope, which appeared in 1608 in the Netherlands, when a patent was submitted by Hans Lippershey, an eyeglass maker. Although Lippershey did not receive his patent, news of the invention soon spread across Europe. The design of these early refracting telescopes consisted of a convex objective lens and a concave eyepiece. Galileo improved on this design the following year and applied it to astronomy. In 1611, Johannes Kepler described how a far more useful telescope could be made with a convex objective lens and a convex eyepiece lens. By 1655, astronomers such as Christiaan Huygens were building powerful but unwieldy Keplerian telescopes with compound eyepieces.
John Lowry Dobson was an American amateur astronomer and is best known for the Dobsonian telescope, a portable, low-cost Newtonian reflector telescope. He was also known for his efforts to promote awareness of astronomy through public lectures including his performances of "sidewalk astronomy". Dobson was also the co-founder of the amateur astronomical group, the San Francisco Sidewalk Astronomers.
A Dobsonian telescope is an altazimuth-mounted Newtonian telescope design popularized by John Dobson in 1965 and credited with vastly increasing the size of telescopes available to amateur astronomers. Dobson's telescopes featured a simplified mechanical design that was easy to manufacture from readily available components to create a large, portable, low-cost telescope. The design is optimized for observing faint, deep-sky objects such as nebulae and galaxies. This type of observation requires a large objective diameter of relatively short focal length and portability for travel to less light-polluted locations.
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.
The Meade Instruments is an American multinational company headquartered in Watsonville, California, that manufactures, imports, and distributes telescopes, binoculars, spotting scopes, microscopes, CCD cameras, and telescope accessories for the consumer market. It is the world's largest manufacturer of telescopes.
Schott AG is a German multinational glass company specializing in the manufacture of glass and glass-ceramics. Headquartered in Mainz, Germany, it is owned by the Carl Zeiss Foundation. The company's founder and namesake, Otto Schott, is credited with the invention of borosilicate glass.
The Maksutov is a catadioptric telescope design that combines a spherical mirror with a weakly negative meniscus lens in a design that takes advantage of all the surfaces being nearly "spherically symmetrical". The negative lens is usually full diameter and placed at the entrance pupil of the telescope. The design corrects the problems of off-axis aberrations such as coma found in reflecting telescopes while also correcting chromatic aberration. It was patented in 1941 by Soviet optician Dmitri Dmitrievich Maksutov. Maksutov based his design on the idea behind the Schmidt camera of using the spherical errors of a negative lens to correct the opposite errors in a spherical primary mirror. The design is most commonly seen in a Cassegrain variation, with an integrated secondary, that can use all-spherical elements, thereby simplifying fabrication. Maksutov telescopes have been sold on the amateur market since the 1950s.
The Schmidt–Cassegrain is a catadioptric telescope that combines a Cassegrain reflector's optical path with a Schmidt corrector plate to make a compact astronomical instrument that uses simple spherical surfaces.
Celestron is a company that manufactures telescopes and distributes telescopes, binoculars, spotting scopes, microscopes, and accessories manufactured by its parent company, the Synta Technology Corporation of Taiwan.
Tele Vue Optics is a Chester, New York-based astronomical optics company known primarily for its premium brand of speciality eyepieces and apochromatic refractor telescopes. Founded in 1977 by Al Nagler, an optical engineer from The Bronx who designed simulators used in the Apollo program, the company originally made projection lenses for large projection-screen televisions, but is well known in the astronomy community for its products.
Questar Corporation is a company based in New Hope, Pennsylvania. It manufactures precision optical devices for consumer, industrial, aerospace, and military markets. Its telescopes produced for the consumer market are sold under the brand name "Questar".
Orion Telescopes & Binoculars is an American retail company that sells telescopes, binoculars and accessories online and in-store for astronomy and birdwatching. It was founded in 1975 and has corporate offices in Watsonville, California. A large proportion of its products are manufactured by the Chinese company Synta for the Orion brand name. Orion Telescopes & Binoculars ships its products to the United States and over 20 other countries. Orion puts out a semi-quarterly mail-order catalog as well as email catalogs. The company is a prominent advertiser in North American astronomy magazines, such as Sky & Telescope and Astronomy.
A Serrurier truss is used in telescope tube assembly construction. The design was created in 1935 by engineer Mark U. Serrurier when he was working on the Mount Palomar 200 in (5.1 m) Hale telescope. The design solves the problem of truss flexing by supporting the primary objective mirror and the secondary mirror by two sets of opposing trusses before and after the declination pivot. The trusses are designed to have an equal amount of flexure, which allows the optics to stay on a common optical axis. When flexing, the "top" truss resists tension and the "bottom" truss resists compression. This has the effect of keeping the optical elements parallel to each other. The net result is all of the optical elements stay in collimation regardless of the orientation of the telescope.
Optical Mechanics, Inc. or OMI is a high-end American telescope and optics instrument manufacturer. OMI was founded in 2002 and produces observatory telescopes, Lidar telescopes, optical tube assemblies, telescope mirrors and reflective coatings for mirrors. OMI mirrors are used by other telescope makers such as Obsession Telescopes. Also taking on custom projects, they produced the 48-inch Dob, a 48.875-inch-diameter (1,241.4 mm) aperture, f/4, Dobsonian telescope called "Barbarella" and featured in Astronomy Technology Today magazine. OMI is located in the US state of Iowa. OMI procured the assets of the former optics company Torus Technologies. OMI has an optics shop where it does work on telescopes.
Obsession Telescopes is an American optical telescope company that specializes in the production of Dobsonian telescopes. The company released the first commercially available Dobsonian telescope. It is also the largest producer of Dobsonian telescopes and operates internationally.
Suzhou Synta Optical Technology Co., Ltd. is a Chinese company located in Suzhou, Jiangsu, China, the primary manufacturing subsidiary of Synta Technology Corporation of Taiwan. It produces telescopes and astronomical equipment like mounts and eyepieces for the amateur astronomical market.
Synta Technology Corporation of Taiwan, also known as Synta, is a manufacturer of telescopes and optical components headquartered in Taoyuan, Taiwan.
Astro-Physics, Inc. is a manufacturer of amateur telescopes, mounts, and accessories. Founded in 1975 by former Sundstrand Corporation engineer Roland Christen, the company is noted for its line of apochromatic refractors as well as high-end mounts. The company is located in Machesney Park, Illinois.
Coretronic Corporation is a Taiwanese electronics and manufacturing company. Founded in Hsinchu Science Park on June 30, 1992, Coretronic is the largest manufacturer of DLP projector, interactive projection system, image signal processing box, projection module, LCD backlight module, touch module, industrial and medical LCD display in Taiwan.
