- symmetrical lens
- noun
: a simple or compound lens whose optical properties are unaltered when the axis is rotated through 180 degrees
Useful english dictionary. 2012.
symmetrical lens
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Lens (geometry) — In geometry, a lens is a convex shape comprising two circular arcs, joined at their endpoints. If the arcs have equal radii, it is called a symmetric lens.The corresponding shape is the lune. The Vesica piscis is one form of a symmetrical lens;… … Wikipedia
Large format lens — Large format lenses are photographic optics that provide an image circle large enough to cover large format film or plates. Large format lenses are typically used in large format cameras and view cameras.Photographic optics generally project a… … Wikipedia
Dialyte lens — A dialyte lens (sometimes called a dialyt[1]) is a compound lens design that corrects optical aberrations where the lens elements are widely air spaced.[2] The design is used to save on the amount of glass used for specific elements or where… … Wikipedia
Contact lens — Contacts redirects here. For the software application, see Address book. A pair of contact lenses, positioned with the concave side facing upward … Wikipedia
Wide-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… … Wikipedia
Dialyt lens — A Dialyt lens is a photographic lens with a symmetrical design consisting of four lenses: the outer pair are biconvex and the inner pair are biconcave. The symmetrical structure provides good correction for many aberrations.The Aviar type of lens … Wikipedia
Plasmat lens — The Plasmat lens is a widely used and long established lens type, especially common in large format photography. It provides high correction of aberrations with a moderate maximum aperture (e.g. f/|5.6|link=yes). In its most basic form it is… … Wikipedia
Axis of a lens — Axis Ax is, n.; pl. {Axes}. [L. axis axis, axle. See {Axle}.] A straight line, real or imaginary, passing through a body, on which it revolves, or may be supposed to revolve; a line passing through a body or system around which the parts are… … The Collaborative International Dictionary of English
Depth of field — The area within the depth of field appears sharp, while the areas in front of and beyond the depth of field appear blurry … Wikipedia
Circle of confusion — For the closely related topic in microscopy, see Point spread function. In optics, a circle of confusion is an optical spot caused by a cone of light rays from a lens not coming to a perfect focus when imaging a point source. It is also known as… … Wikipedia
