Amateur astronomy is a hobby where participants enjoy observing or imaging celestial objects in the sky using the unaided eye, binoculars, or telescopes. Even though scientific research may not be their primary goal, some amateur astronomers make contributions in doing citizen science, such as by monitoring variable stars, double stars, sunspots, or occultations of stars by the Moon or asteroids, or by discovering transient astronomical events, such as comets, galactic novae or supernovae in other galaxies.
A monocular is a compact refracting telescope used to magnify images of distant objects, typically using an optical prism to ensure an erect image, instead of using relay lenses like most telescopic sights. The volume and weight of a monocular are typically less than half of a pair of binoculars with similar optical properties, making it more portable and also less expensive. This is because binoculars are essentially a pair of monoculars packed together — one for each eye. As a result, monoculars only produce two-dimensional images, while binoculars can use two parallaxed images to produce binocular vision, which allows stereopsis and depth perception.
Carl Zeiss AG, branded as ZEISS, is a German manufacturer of optical systems and optoelectronics, founded in Jena, Germany in 1846 by optician Carl Zeiss. Together with Ernst Abbe and Otto Schott he laid the foundation for today's multinational company. The current company emerged from a reunification of Carl Zeiss companies in East and West Germany with a consolidation phase in the 1990s. ZEISS is active in four business segments with approximately equal revenue in almost 50 countries, has 30 production sites and around 25 development sites worldwide.
An eyepiece, or ocular lens, is a type of lens that is attached to a variety of optical devices such as telescopes and microscopes. It is named because it is usually the lens that is closest to the eye when someone looks through an optical device to observe an object or sample. The objective lens or mirror collects light from an object or sample and brings it to focus creating an image of the object. The eyepiece is placed near the focal point of the objective to magnify this image to the eyes. The amount of magnification depends on the focal length of the eyepiece.
The Meade Instruments was 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 was, at one point, the world's largest manufacturer of telescopes.
In optics, the exit pupil is a virtual aperture in an optical system. Only rays which pass through this virtual aperture can exit the system. The exit pupil is the image of the aperture stop in the optics that follow it. In a telescope or compound microscope, this image is the image of the objective element(s) as produced by the eyepiece. The size and shape of this disc is crucial to the instrument's performance, because the observer's eye can see light only if it passes through the aperture. The term exit pupil is also sometimes used to refer to the diameter of the virtual aperture. Older literature on optics sometimes refers to the exit pupil as the Ramsden disc, named after English instrument-maker Jesse Ramsden.
Digiscoping is a neologism for afocal photography, using a (digital) camera to record distant images through the eyepiece of an optical telescope.
Celestron, LLC 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.
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 was an American retail company that sold telescopes, binoculars and accessories online and in-store for astronomy and birdwatching. It was founded in 1975 and had corporate offices in Watsonville, California. A large proportion of its products were manufactured by the Chinese company Synta for the Orion brand name. Orion Telescopes & Binoculars shipped its products to the United States and over 20 other countries. Orion put out a semi-quarterly mail-order catalog as well as email catalogs. The company was a prominent advertiser in North American astronomy magazines, such as Sky & Telescope and Astronomy.
Bushnell Corporation is an American firm that specializes in sporting optics and outdoor products. It is based in Overland Park, Kansas and is a wholly-owned subsidiary of Vista Outdoor. Bushnell makes binoculars, telescopes, spotting scopes, riflescopes, red dot sights, GPS devices, laser rangefinders, game cameras, night-vision devices and other optical equipments.
Unitron is a US-based company and distributor of optical instruments including stereo microscopes and accessories, binoculars, and classic brass telescopes. The company was founded in 1952 by Lawrence A. Fine as the United Trading Company and located in Boston, MA. He registered the UNITRON trademark in the United States for first use in commerce in February, 1952. The company started out importing smaller that were manufactured by Nihon Seiko of Japan. By 1961 Unitron expanded the product line to include 5" and 6" models that were suited for observatory use. A very small number of the 5" and 6" models were produced. Several of the 6" Model 620's remain operational at observatories to include: Rafes Urban Astronomy Center, Denton, Texas; Castleton State College, Castleton, Vermont, Ferris State University, Big Rapids, Michigan, and the University of Connecticut, Storrs, Connecticut.
Tasco sells consumer telescopes. Tasco mainly imports telescopes for amateur astronomers but has expanded into other optical products, such as spotting scopes, microscopes, binoculars, telescopic sights, and other rifle accessories. Tasco sells via retail stores, catalogs, and online retailers. Tasco is based in Miramar, Florida. George Rosenfield founded the firm as the Tanross Supply Company in 1954. It started as a distributor of fishing tackle and hardware. The name was later shortened to Tasco as its offerings expanded to include binoculars and eyepieces.
Swarovski Optik is a division of the Swarovski group of companies, manufacturing optical instruments. Its headquarters are located in Absam, Tyrol, Austria.
NOBLEX E-Optics GmbH, formerly Docter Optics, is a German manufacturer of optics, including binoculars, rifle scopes, spotting scopes, red dot sights, flashlights and reading glasses. Its headquarters are in Eisfeld, Thuringia, Germany, where most of the products are developed and manufactured. Docter is part of the Analytik Jena Group.
Leica Microsystems GmbH is a German microscope manufacturing company. It is a manufacturer of optical microscopes, equipment for the preparation of microscopic specimens and related products. There are ten plants in eight countries with distribution partners in over 100 countries. Leica Microsystems emerged in 1997 out of a 1990 merger between Wild-Leitz, headquartered in Heerbrugg Switzerland, and Cambridge Instruments of Cambridge England. The merger of those two umbrella companies created an alliance of the following 8 individual manufacturers of scientific instruments. American Optical Scientific Products, Carl Reichert Optische Werke AG, R.Jung, Bausch and Lomb Optical Scientific Products Division, Cambridge Instruments, E.Leitz Wetzlar, Kern & Co., and Wild Heerbrugg AG, bringing much-needed modernization and a broader degree of expertise to the newly created entity called Leica Holding B.V. group. In 1997 the name was changed to Leica Microsystems and is a wholly-owned entity of Danaher Corporation since July 2005. Danaher is a US venture capital company.
The Bresser Corporation is a Germany-based manufacturer and distributor of optical devices such as binoculars, astronomical telescopes,microscopes. In addition, the company also has a separate consumer electronics division for weather stations and action cameras since 2016. The main supplier for the company is Jinghua Optical & Electronics Co., Ltd. (JOC).
W. Watson and Son was an optical instrument maker. In 1837, the William Watson business was established in London for the manufacture of optical instruments. By the 1840s, the company moved into lanterns, slides and associated equipment. In 1868, the name was changed to W. Watson & Son and by this time were located at 313 High Holborn, London. In the 1870s, the company added photographic equipment and became known as a leading manufacturer of the Highest Class Photographic Instruments and Apparatus in England. Into the 1940s, the company remained at 313 High Holborn.
Denis Albert Bardou was a French manufacturer of precision optical instruments.
Steiner-Optik is a manufacturer of optical equipment for the military, hunting and marine sector. The company is headquartered in Bayreuth, northern Bavaria, and has been part of the Beretta Group since 2008. Steiner manufactures products for the civilian market as well as for the defense industry. Its product range includes binoculars for military and police use, rifle scope sights and spotting scopes for hunting, seafaring, outdoor and ornithology. Every year 200,000 to 250,000 binoculars are produced, of which 80% are exported.
