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  2. Schmidt–Pechan prism - Wikipedia

    en.wikipedia.org/wiki/Schmidt–Pechan_prism

    A Schmidt–Pechan prism is a type of optical prism used to rotate an image by 180°. These prisms are commonly used in binoculars as an image erecting system. The Schmidt–Pechan prism makes use of a roof prism section (from the German: "Dachkante", lit. roof edge ). Binoculars designs using Schmidt–Pechan prisms can be constructed more ...

  3. Astigmatism - Wikipedia

    en.wikipedia.org/wiki/Astigmatism

    However, there are many ways to help correct astigmatisms: The use of glasses or contacts, Toric intraocular lenses, Toric implantable Collamer lenses, and/or corneal refractive surgery have been shown to correct astigmatisms. History. As a student, Thomas Young discovered that he had problems with one eye in 1793.

  4. Achromatic lens - Wikipedia

    en.wikipedia.org/wiki/Achromatic_lens

    In an achromatic lens, two wavelengths are brought into the same focus, here red and blue. An achromatic lens or achromat is a lens that is designed to limit the effects of chromatic and spherical aberration. Achromatic lenses are corrected to bring two wavelengths (typically red and blue) into focus on the same plane.

  5. PRISM (reactor) - Wikipedia

    en.wikipedia.org/wiki/PRISM_(reactor)

    The S-PRISM represents GEH's Generation IV reactor solution to closing the nuclear fuel cycle and is also part of its Advanced Recycling Center (ARC) proposition [1] to U.S. Congress to deal with nuclear waste. [2] S-PRISM is a commercial implementation of the Integral Fast Reactor developed by Argonne National Laboratory between 1984 and 1994.

  6. Petzval lens - Wikipedia

    en.wikipedia.org/wiki/Petzval_lens

    Petzval portrait 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].

  7. Vertex distance - Wikipedia

    en.wikipedia.org/wiki/Vertex_distance

    Vertex distance is the distance between the back surface of a corrective lens, i.e. glasses (spectacles) or contact lenses, and the front of the cornea. Increasing or decreasing the vertex distance changes the optical properties of the system, by moving the focal point forward or backward, effectively changing the power of the lens relative to ...

  8. Fresnel equations - Wikipedia

    en.wikipedia.org/wiki/Fresnel_equations

    Since the Fresnel equations were developed for optics, they are usually given for non-magnetic materials. Dividing ( 4) by ( 5 )) yields. For non-magnetic media we can substitute the vacuum permeability μ0 for μ, so that that is, the admittances are simply proportional to the corresponding refractive indices.

  9. Catadioptric system - Wikipedia

    en.wikipedia.org/wiki/Catadioptric_system

    A catadioptric optical system is one where refraction and reflection are combined in an optical system, usually via lenses ( dioptrics) and curved mirrors ( catoptrics ). Catadioptric combinations are used in focusing systems such as searchlights, headlamps, early lighthouse focusing systems, optical telescopes, microscopes, and telephoto lenses.