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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.
This is a list of United States Army fire control, and sighting material by supply catalog designation, or Standard Nomenclature List (SNL) group "F".The United States Army Ordnance Corps Supply Catalog used an alpha-numeric nomenclature system from about the mid-1920s to about 1958.
Additionally, Tele Vue eyepieces are well corrected for most aberrations, providing edge to edge pinpoint stars, and are well suited to use in popular "fast" telescopes. The most expensive Tele Vue eyepiece is the Ethos line, which consists of eight eyepieces known for excellent image quality and ultra-wide 100 degree fields, which can retail ...
The first of these was the Hamiltonian telescope patented by W. F. Hamilton in 1814. The Schupmann medial telescope designed by German optician Ludwig Schupmann near the end of the 19th century placed the catadioptric mirror beyond the focus of the refractor primary and added a third correcting/focusing lens to the system.
Galilean type Soviet-made miniature 2.5 × 17.5 monocular Diagram of a monocular using a Schmidt-Pechan prism: 1 – Objective lens 2 – Schmidt-Pechan prism 3 – Eyepiece. 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 ads focused on the telescope's mechanical and optical design, educational value for children, ease of use, and adaptations as a spotting scope and telephoto lens. The Questar of the 1950s and early 1960s had a proprietary screw in eyepiece design and offered little capacity to employ third-party accessories.
Cheshire eyepiece, combined with a sight tube and crosshairs. A Cheshire eyepiece or Cheshire collimator is a simple tool that helps aligning the optical axes of the mirrors or lenses of a telescope, a process called collimation. It consists of a peephole to be inserted into the focuser in place of the eyepiece.
The National Imagery Interpretability Rating Scale (NIIRS) is an American subjective scale used for rating the quality of imagery acquired from various types of imaging systems. The NIIRS defines different levels of image quality/interpretability based on the types of tasks an analyst can perform with images of a given NIIRS rating.