enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Fresnel lens - Wikipedia

    en.wikipedia.org/wiki/Fresnel_lens

    A Fresnel lens (/ ˈ f r eɪ n ɛ l,-n əl / FRAY-nel, -⁠nəl; / ˈ f r ɛ n ɛ l,-əl / FREN-el, -⁠əl; or / f r eɪ ˈ n ɛ l / fray-NEL [1]) is a type of composite compact lens which reduces the amount of material required compared to a conventional lens by dividing the lens into a set of concentric annular sections.

  3. Petzval lens - Wikipedia

    en.wikipedia.org/wiki/Petzval_lens

    The Petzval objective, or Petzval lens, is the first photographic portrait objective lens (with a 160 mm focal length) in the history of photography. [1] It was developed by the Slovak mathematics professor Joseph Petzval in 1840 in Vienna , [ 2 ] with technical advice provided by Peter Wilhelm Friedrich von Voigtländer [ de ] .

  4. Aspheric lens - Wikipedia

    en.wikipedia.org/wiki/Aspheric_lens

    A single aspheric lens can often replace a much more complex multi-lens system. The resulting device is smaller and lighter, and sometimes cheaper than the multi-lens design. [ 1 ] Aspheric elements are used in the design of multi-element wide-angle and fast normal lenses to reduce aberrations.

  5. Eyeglass prescription - Wikipedia

    en.wikipedia.org/wiki/Eyeglass_prescription

    Using a phoropter to determine a prescription for eyeglasses. An eyeglass prescription is an order written by an eyewear prescriber, such as an optometrist, that specifies the value of all parameters the prescriber has deemed necessary to construct and/or dispense corrective lenses appropriate for a patient.

  6. Achromatic lens - Wikipedia

    en.wikipedia.org/wiki/Achromatic_lens

    Uses an equiconvex crown glass lens (i.e. R 1 > 0 with −R 1 = R 2) and a complementary-curved second flint glass lens (with R 3 = R 2). The back of the flint glass lens is flat ( R 4 = ∞). A Littrow doublet can produce a ghost image between R 2 and R 3 because the lens surfaces of the two lenses have the same radii.

  7. Boris RED - Wikipedia

    en.wikipedia.org/wiki/Boris_RED

    Lens Blur The multi-core optimized lens blur filter emulates the circular or multi-sided iris shaped highlights that are generated with real camera lenses. Lens Shape The multi-processor accelerated BCC Lens Shape filter to generate stylized image highlights that take their shape from an alternate alpha image source.

  8. Spherical coordinate system - Wikipedia

    en.wikipedia.org/wiki/Spherical_coordinate_system

    In mathematics, a spherical coordinate system is a coordinate system for three-dimensional space where the position of a given point in space is specified by three real numbers: the radial distance r along the radial line connecting the point to the fixed point of origin; the polar angle θ between the radial line and a polar axis; and the ...

  9. Lens - Wikipedia

    en.wikipedia.org/wiki/Lens

    A compound lens is a collection of simple lenses of different shapes and made of materials of different refractive indices, arranged one after the other with a common axis. In a multiple-lens system, each lens treats the previous lens's image as an object, and produces a new image of it, so that the imaging is cascaded through the lenses.