focus of lens
81Canon EF 500mm lens — Infobox photographic lenses name = EF 500mm f4/L USM caption = From left to right : EF 28 300mm f/3.5 5.6L IS USM, 70 200 f/2.8L IS USM, 300mm f/2.8L IS USM, 500mm f/4L IS USM maker = Canon feat is = y feat usm = y feat sbf = feat macro = feat… …
82Telephoto lens — Portal|Photography|Large format camera lens.jpg created by a telephoto lens is the same as that created by an ordinary lens of the same specified focal length. Construction If a camera lens were to be constructed from a single lens of 200 mm… …
83Single-lens reflex camera — The single lens reflex (SLR) camera uses an automatic moving mirror system which permits the photographer to see exactly what will be captured by the film or digital imaging system, as opposed to non SLR cameras where the view through the… …
84Wide-angle lens — In photography and cinematography, a wide angle lens is a lens whose focal length is substantially shorter than the focal length of a normal lens for the image size produced by the camera, whether this is dictated by the dimensions of the image… …
85Parfocal lens — A parfocal lens is a lens that stays in focus when magnification/focal length is changed. There is inevitably some amount of focus error, but small enough not to be considered significant.MicroscopyParfocal microscope objectives stay in focus… …
86Manual focus — In the field of photography, a manual focus camera is one in which the operator has to adjust the focus of the lens by hand. Before the advent of autofocus, all cameras had manually adjusted focusing; thus, the term is a retronym. The focus… …
87Minolta AF 500mm Reflex lens — Minolta 500mm f/8 Reflex Key features Maker: Minolta, Sony Ultrasonic motor:  No Macro capable …
88Canon EF 1200mm lens — Infobox photographic lenses name = EF 1200mm f/5.6L USM caption = maker = Canon feat is = n feat usm = y feat sbf = feat macro = feat special = type = p application = Super Telephoto flength = 1200mm fov = aperture = f/5.6 f/32 groups = 10… …
89Adjustable focus — eyeglasses compensate for the effects of presbyopia, lack of focusing, by providing on demand clarity at any desired distance.Two approaches can be found in the literature: electro optical (often utilizing liquid crystals as the active medium)… …
90Fresnel lens — A Fresnel lens (pronounced [ frɛz.nəl] or [freɪ nɛl] ) is a type of lens invented by French physicist Augustin Jean Fresnel. Originally developed for lighthouses, the design enables the construction of lenses of large aperture and short focal… …
