focal plane

focal plane
The plane occupied by the film at the focal point of the lens. It can be positive or negative; it is commonly referred to as positive and negative planes, respectively.
i. The meteorological condition in which the horizontal visibility at the earth’s surface is less than 1000 m because of suspended small droplets or ice crystals in the air. Relative humidity in this case is generally 100% but not less than 95%. Fog is formed by the cooling of the air by contact and mixing or, occasionally, through saturation of the air by increasing water content. Fogs are classified according to their effect on visibility: in dense fog, visibility is less than 50 m; in thick fog, visibility is between 50 and 200 m; in fog, visibility is between 200 and 500 m; in moderate fog, visibility is between 500 m and 1000 m; and in thin fog, visibility is between 1000 and 1500 m.
ii. As it relates to aerial photography, a darkening of negatives or prints because of a deposit of silver that does not form a part of the image. Fog tends to increase density and decrease the contrast. It can be caused by exposure to unwanted light, to air during development, to impure chemicals, etc.

Aviation dictionary. 2014.

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Look at other dictionaries:

  • focal plane — n a plane that is perpendicular to the axis of a lens or mirror and passes through the focus …   Medical dictionary

  • focal plane — židinio plokštuma statusas T sritis fizika atitikmenys: angl. focal plane vok. Brennebene, f; Fokalebene, f rus. фокальная плоскость, f pranc. plan focal, m …   Fizikos terminų žodynas

  • focal plane — židinio plokštuma statusas T sritis Gynyba apibrėžtis Lęšio optinei ašiai statmena plokštuma, kurioje yra sufokusuotas vaizdas, matomas objektyve. atitikmenys: angl. focal plane pranc. plan focal …   NATO terminų aiškinamasis žodynas

  • Focal-plane shutter — In camera design, a focal plane shutter is a type of photographic shutter that is positioned immediately in front of the focal plane of the camera, that is, right in front of the photographic film or image sensor. AdvantagesOne of the main… …   Wikipedia

  • Focal plane array testing — (under development sep 15)Focal Plane Array testing (FPA testing) is the test engineering process of validation and verification (V V) of operation of focal plane array imaging devices, device under test (DUT), at various levels of the… …   Wikipedia

  • focal-plane shutter — noun : a camera shutter used chiefly for instantaneous exposures in which a slit in an opaque curtain is passed directly across and in front of the film near the focal plane, the width of the slit and the speed of its movement determining the… …   Useful english dictionary

  • focal plane — Optics. 1. a plane through a focal point and normal to the axis of a lens, mirror, or other optical system. Cf. principal plane. 2. the transverse plane in a telescope where the real image of a distant view is in focus. [1890 95] * * * …   Universalium

  • focal plane — /ˈfoʊkəl pleɪn/ (say fohkuhl playn) noun 1. the plane normal to the principal axis of a lens (or system of lenses) or a mirror, which passes through the focal point. 2. the plane in which light rays from an external object are focused in a camera …  

  • focal plane —    In photography, an image line at right angle to the optical axis passing through the focal point. This forms the plane of sharp focus when a camera is set on infinity. Also see aperture, camera, focal length, and f/stop …   Glossary of Art Terms

  • focal plane — fo′cal plane n. opt a plane through a focal point and perpendicular to the axis of a lens, mirror, or other optical system • Etymology: 1890–95 …   From formal English to slang

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