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PLate OPtimizer, or PLOP is a CAD program used by amateur telescope makers to design primary mirror support cells for reflecting telescopes.It was developed by telescope maker David Lewis, first described in 1999, [1] and used to simplify calculations needed in the design of mirror support cells. [2]
The material exhibits a particularly low thermal expansion, with a mean value of 0 ± 0.007×10 −6 K −1 within the temperature range of 0 to 50 °C. [22] High 3D homogeneity [22] with few inclusions, bubbles and internal stria. Hardness similar to that of borosilicate glass. High affinity for coatings. Low helium permeability. Non-porous.
The Meade LX200 is a family of commercial telescopes produced by Meade Instruments launched in 1992 with 8" (20.32 cm) and a 10" (25.4 cm) Schmidt–Cassegrain models on computerized altazimuth mounts. [1] [2] Two larger models, a 12" (30.48 cm) and a 16" (40.64 cm), quickly
Primary lens: The objective of a refracting telescope. Primary mirror: The objective of a reflecting telescope. Corrector plate: A full aperture negative lens placed before a primary mirror designed to correct the optical aberrations of the mirror. Schmidt corrector plate: An aspheric-shaped corrector plate used in the Schmidt telescope.
Light path in a Klevtsov-Cassegrain reflector telescope In the Klevtsov-Cassegrain, all of the optical surfaces are spherical or near-spherical. [ 1 ] [ 2 ] The secondary Mangin mirror ( M 2 ) and the meniscus corrector ( C ) are held in place by a spider vane and the front of the telescope tube is otherwise open.
Given as the first number in a binocular description (e.g., 7×35, 10×50), magnification is the ratio of the focal length of the objective divided by the focal length of the eyepiece. This gives the magnifying power of binoculars (sometimes expressed as "diameters").
Comparison of nominal sizes of apertures of the Hobby–Eberly Telescope and some notable optical telescopes. The Hobby–Eberly Telescope (HET) is a 10-meter (30-foot) aperture telescope located at the McDonald Observatory in Davis Mountains, Texas. The Hobby–Eberly Telescope is one of the largest optical telescopes in the world.
Photon sieve. A photon sieve is a device for focusing light using diffraction and interference.It consists of a flat sheet of material full of pinholes that are arranged in a pattern which is similar to the rings in a Fresnel zone plate, but with the ability to bring light to much sharper focus.