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A copyscope is type of refracting telescope that can be made by hand rather than bought in which the objective lens comes from an old photocopy machine, hence the origin of the name. [1] The lenses usually come from defective or old photocopiers, allowing for the objective to be obtained for free or at a low cost.
A 6-inch (15 cm) Newtonian reflector built by a school student on display at Stellafane Although the types of telescopes that amateurs build vary widely, including Refractors, Schmidt–Cassegrains and Maksutovs, the most popular telescope design is the Newtonian reflector, [3] described by Russell W. Porter as "The Poor Man's Telescope".
The idea of using the spherical aberration of a meniscus lens to correct the opposite aberration in a spherical objective dates back as far as W. F. Hamilton’s 1814 Hamiltonian telescope, in Colonel A. Mangin's 1876 Mangin mirror, and also appears in Ludwig Schupmann’s Schupmann medial telescope near the end of the 19th century.
A Schmidt corrector plate is an aspheric lens which corrects the spherical aberration introduced by the spherical primary mirror of the Schmidt or Schmidt–Cassegrain telescope designs. It was invented by Bernhard Schmidt in 1931, [ 6 ] although it may have been independently invented by Finnish astronomer Yrjö Väisälä in 1924 (sometimes ...
The force of gravity (red), the buoyancy force (green), and the resultant centripetal force (blue) In the following discussion, represents the acceleration due to gravity, represents the angular speed of the liquid's rotation, in radians per second, is the mass of an infinitesimal parcel of liquid material on the surface of the liquid, is the distance of the parcel from the axis of rotation ...
A Fresnel imager is a proposed ultra-lightweight design for a space telescope that uses a Fresnel array as primary optics instead of a typical lens. It focuses light with a thin opaque foil sheet punched with specially shaped holes, thus focusing light on a certain point by using the phenomenon of diffraction.
When Edmund Scientific introduced the telescope in 1976 they called it "The Edmund Wide-Field Telescope" with a Part Number "2001" [5] Edmund had a public contest which ran until November 15, 1976, to come up with a name. [6] The winning name was "Astroscan 2001". The "2001" part of the name was dropped over time.
This had a visual objective lens of 32.7 inches on one tube, and alongside it another tube with a lens of 24.4 inches intended for photographic work. [31] An example of converting to photographic work with a third corrector lens is the Lick telescope. [31] A 33-inch corrector lens was used to convert this telescope for photography. [31]