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Binoculars or field glasses are two telescopes mounted side-by-side and aligned to point in the same direction, allowing the viewer to use both eyes (binocular vision) when viewing distant objects. Most are sized to be held using both hands, although sizes vary widely from opera glasses to large pedestal mounted military models.
Porro prism binoculars are named after Italian optician Ignazio Porro, who patented this image erecting system in 1854. This system was later refined by other binocular makers, notably the Carl Zeiss company in the 1890s.[1] Binoculars of this type use a pair of Porro prisms in a Z-shaped configuration to erect the image. This results in binoculars that are wide, with objective lenses that are well separated and offset from the eyepieces, giving a better sensation of depth. Porro prism designs have the added benefit of folding the optical path so that the physical length of the binoculars is less than the focal length of the objective. Although Porro prism binoculars were made in such a way to erect image in a small space, thus using prism was started in this way.
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Category: Cameras and Photography:Telescopes and Binoculars:Binoculars and Monoculars
Location: THESSALONIKI