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This list covers optical lens designs grouped by tasks or overall type. The field of optical lens designing has many variables including the function the lens or group of lenses have to perform, the limits of optical glass because of the index of refraction and dispersion properties, and design constraints including realistic lens element center and edge thicknesses, minimum and maximum air ...
A lens contained between two circular arcs of radius R, and centers at O 1 and O 2. In 2-dimensional geometry, a lens is a convex region bounded by two circular arcs joined to each other at their endpoints. In order for this shape to be convex, both arcs must bow outwards (convex-convex).
Leonardo da Vinci's Vitruvian Man (c. 1485) Accademia, Venice. Drawing is a visual art that uses an instrument to mark paper or another two-dimensional surface. The instruments used to make a drawing are pencils, crayons, pens with inks, brushes with paints, or combinations of these, and in more modern times, computer styluses with graphics tablets or gamepads in VR drawing software.
Consequently, for external lens surfaces as diagrammed above, R 1 > 0 and R 2 < 0 indicate convex surfaces (used to converge light in a positive lens), while R 1 < 0 and R 2 > 0 indicate concave surfaces. The reciprocal of the radius of curvature is called the curvature. A flat surface has zero curvature, and its radius of curvature is infinite.
However, for the record: the first autofocus lens for a still camera was the Konishiroku Konica Hexanon 38mm f/2.8 [171] built into the Konica C35 AF (1977, Japan) 35mm point-and-shoot; the first autofocus lens for an SLR camera was the unnamed 116mm f/8 [172] built into the Polaroid SX-70 Sonar (1978, USA) instant film SLR; the first ...
On a Nikon DX format DSLR, a 50 mm lens is cropped to the angle of a view of a short telephoto lens (~75 mm equivalent; field-of-view crop is 1.54). Prime lenses can be cheaper and easier to manufacture than zoom lenses, and may have better optical characteristics compared with zoom lenses of comparable price.
A simple zoom lens system. The three lenses of the afocal system are L 1, L 2, L 3 (from left). L 1 and L 2 can move to the left and right, changing the overall focal length of the system (see image below). There are many possible designs for zoom lenses, the most complex ones having upwards of thirty individual lens elements and multiple ...
Peleng 3.5/8A is an 8 mm super-wideangle circular fisheye photographic lens, and is designed as an interchangeable lens for Canon, Nikon, Pentax, Olympus digital or film cameras which have or do not have the instant-return diaphragm automatic control device [clarification needed]. The lens has a variable diaphragm from f/3.5 to f/16.