focal distance

focal distance
(of the eye) the distance between the lens and the point behind the lens at which light from a distant object is focused. In a normally sighted person the point of focus is on the retina, but in myopia (short-sightedness) the focus is in front of the retina and in hypermetropia (long-sightedness) the point of focus is beyond the retina.

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the distance from the focal point to the optical center of a lens or the surface of a concave mirror.

Medical dictionary. 2011.

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Look at other dictionaries:

  • focal distance — noun the distance from a lens to its focus • Syn: ↑focal length • Hypernyms: ↑distance * * * focal distance noun Focal length • • • Main Entry: ↑focus * * * …   Useful english dictionary

  • focal distance — židinio nuotolis statusas T sritis Standartizacija ir metrologija apibrėžtis Atstumas tarp pagrindinės glaudžiamojo lęšio plokštumos ir jo židinio taško. atitikmenys: angl. focal distance; focal length vok. Brennweite, f; Fokalweite, f rus.… …   Penkiakalbis aiškinamasis metrologijos terminų žodynas

  • focal distance — židinio nuotolis statusas T sritis Standartizacija ir metrologija apibrėžtis Atstumas tarp plonojo lęšio centro ir židinio. atitikmenys: angl. focal distance; focal length vok. Brennweite, f; Fokalweite, f rus. фокусное расстояние, n pranc.… …   Penkiakalbis aiškinamasis metrologijos terminų žodynas

  • focal distance — židinio nuotolis statusas T sritis fizika atitikmenys: angl. focal distance vok. Brennweite, f rus. фокусное расстояние, n pranc. distance focale, f …   Fizikos terminų žodynas

  • Focal distance of a telescope — Focal Fo cal, a. [Cf. F. focal. See {Focus}.] Belonging to,or concerning, a focus; as, a focal point. [1913 Webster] {Focal distance, or length, of a lens or mirror} (Opt.), the distance of the focus from the surface of the lens or mirror, or… …   The Collaborative International Dictionary of English

  • Focal distance or length of a lens or mirror — Focal Fo cal, a. [Cf. F. focal. See {Focus}.] Belonging to,or concerning, a focus; as, a focal point. [1913 Webster] {Focal distance, or length, of a lens or mirror} (Opt.), the distance of the focus from the surface of the lens or mirror, or… …   The Collaborative International Dictionary of English

  • focal distance — distance from the center of a lens to the point of focus …   English contemporary dictionary

  • focal distance — (of the eye) the distance between the lens and the point behind the lens at which light from a distant object is focused. In a normally sighted person the point of focus is on the retina, but in myopia (short sightedness) the focus is in front of …   The new mediacal dictionary

  • Focal distance — Фокусное расстояние (объектива); Фокусное расстояние …   Краткий толковый словарь по полиграфии

  • Flange focal distance — The flange focal distance (FFD) (also known as the flange to film distance, flange focal depth, flange back distance (FBD), or register, depending on the usage and source) of a lens mount for an interchangeable lens camera system is one of its… …   Wikipedia

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