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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]
Speculum mirrors tarnished rapidly; with two mirrors, one could be used in the telescope while the other was being re-polished. The telescope tube and supporting structure were completed in 1845. [2] A 1:24 model of the telescope made by Parsons in 1844-45. The mirror was 5 inches (13 cm) thick and weighed almost 3 tons.
Telecompressor or focal reducer: Optical element to decrease the telescope's focal length and magnification (usually by a fixed percentage) and widen the field of view, providing opposite effects of a Barlow lens. Star Diagonal: Used to change the angle of the light coming out of a telescope, for easier viewing.
The addition of a focusing lens reduces the light transmission of the optical system contained in the telescope tube somewhat. Internal focusing is generally considered the mechanically more robust central focusing solution and with the help of an appropriate seal like O-rings air and moisture ingress can be prevented, to make binoculars fully ...
The main tube of telescopic sights varies in size, material, the applied production process and surface finish. The typical outside diameters vary between 19.05 mm (0.75 in) and 40 mm (1.57 in), although 25.4 mm (1 in), 30 mm and recently 34 mm are by far the most common sizes.
Although speculum metal mirror reflecting telescopes could be built very large, such as William Herschel's 126-cm (49.5-inch) "40-foot telescope" of 1789 and Lord Rosse 183-cm (72-inch) mirror of his "Leviathan of Parsonstown" of 1845, impracticalities in using the metal made most astronomers prefer their smaller refracting telescope ...
The RCT has a wider field of view free of optical errors compared to a more traditional reflecting telescope configuration. Since the mid 20th century, a majority of large professional research telescopes have been Ritchey–Chrétien configurations; some well-known examples are the Hubble Space Telescope , the Keck telescopes and the ESO Very ...
Optical instruments like microscopes, telescopes, and DSLRs all have optical trains that guide the incoming light towards a detector or the eye of an observer. The optical train of a telescope is commonly called an optical tube assembly ( OTA ) or simply an optical tube .