Lens speed — refers to the maximum aperture diameter, or minimum f number, of a photographic lens. A lens with a larger maximum aperture (that is, a smaller minimum f number) is a fast lens because it delivers more light intensity (illuminance) to the focal… … Wikipedia
Lens (riviere) — Lens (rivière) Lens Photo souhaitée Merci Caractéristiques Longueur 25,7 km Bassin 62 km2 Bassin collecteur Garonne … Wikipédia en Français
Lens (rivière) — Lens Photo souhaitée Merci Caractéristiques Longueur 25,7 km Bassin 62 km2 Bassin collecteur Garonne Débit moyen 0,64 m3 … Wikipédia en Français
Lens sag — is a problem that sometimes afflicts very large refracting telescopes. It is the equivalent of mirror sag in reflecting telescopes. It occurs when the physical weight of the glass causes a distortion in the shape of the lens because the lens can… … Wikipedia
Lens space — A lens space is an example of a topological space, considered in mathematics. The term often refers to a specific class of 3 manifolds, but in general can be defined for higher dimensions.In the 3 manifold case, a picturesque description of a… … Wikipedia
equivalent focal length — noun or equivalent focus : the focal length of a single thin lens that would best duplicate the images formed by a given thick lens, compound lens, or lens system … Useful english dictionary
Canon FL 1200mm lens — The Canon FL 1200mm f/11 was a super telephoto lens marketed by Japanese optical manufacturer Canon in June 1972. It was the longest super telephoto lens in the Canon FL system. Canon did not release an equivalent lens for the Canon FD mount, and … Wikipedia
Canon EF-S 17-85mm lens — Infobox photographic lenses name = EF S 17–85mm f/4 5.6 IS USM maker = Canon feat is = y feat usm = y feat sbf = y feat macro = n feat special = type = s application = Standard flength = 17–85mm (35 mm equivalent of 27.2–136mm) fov = aperture =… … Wikipedia
Canon EF-S 17-55mm lens — Infobox photographic lenses name = EF S 17 55mm f/2.8 IS USM maker = Canon feat is = y feat usm = y feat sbf = y feat macro = n feat special = type = s application = Standard flength = 17 55mm (35 mm equivalent of 27 88mm) fov = aperture = f/2.8… … Wikipedia
35 mm equivalent focal length — In photography, the 35 mm equivalent focal length is a measure that indicates the angle of view of a particular combination of a camera lens and film or sensor size. The term originates from the time when the vast majority of photography was done … Wikipedia