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  2. Foucault knife-edge test - Wikipedia

    en.wikipedia.org/wiki/Foucault_knife-edge_test

    Viewing the mirror from behind the knife edge shows a pattern on the mirror surface. If the mirror surface is part of a perfect sphere, the mirror appears evenly lighted across the entire surface. If the mirror is spherical but with defects such as bumps or depressions, the defects appear greatly magnified in height.

  3. Foucault's measurements of the speed of light - Wikipedia

    en.wikipedia.org/wiki/Foucault's_measurements_of...

    The light reflected back from the spherical mirrors is diverted by beam splitter g towards an eyepiece O. If mirror m is stationary, both images of the slit reflected by M and M' reform at position α. If mirror m is rapidly rotating, light reflected from M forms an image of the slit at α' while light reflected from M' forms an image of the ...

  4. Geometrical optics - Wikipedia

    en.wikipedia.org/wiki/Geometrical_optics

    In particular, spherical mirrors exhibit spherical aberration. Curved mirrors can form images with magnification greater than or less than one, and the image can be upright or inverted. An upright image formed by reflection in a mirror is always virtual, while an inverted image is real and can be projected onto a screen. [3]

  5. Null corrector - Wikipedia

    en.wikipedia.org/wiki/Null_corrector

    The test only requires that the pinhole be located at the center of sphere defined by the mirror's surface. A null corrector is an optical device used in the testing of large aspheric mirrors. A spherical mirror of any size can be tested relatively easily using standard optical components such as laser, mirrors, beamsplitters, and converging ...

  6. Curved mirror - Wikipedia

    en.wikipedia.org/wiki/Curved_mirror

    Spherical mirrors, however, suffer from spherical aberration—parallel rays reflected from such mirrors do not focus to a single point. For parallel rays, such as those coming from a very distant object, a parabolic reflector can do a better job. Such a mirror can focus incoming parallel rays to a much smaller spot than a spherical mirror can.

  7. Transfer-matrix method (optics) - Wikipedia

    en.wikipedia.org/wiki/Transfer-matrix_method...

    The transfer-matrix method is a method used in optics and acoustics to analyze the propagation of electromagnetic or acoustic waves through a stratified medium; a stack of thin films. [ 1 ] [ 2 ] This is, for example, relevant for the design of anti-reflective coatings and dielectric mirrors .

  8. Reflection mapping - Wikipedia

    en.wikipedia.org/wiki/Reflection_mapping

    An environment texture mapped onto models of spoons, to give the illusion that they are reflecting the world around them. In computer graphics, reflection mapping or environment mapping [1] [2] [3] is an efficient image-based lighting technique for approximating the appearance of a reflective surface by means of a precomputed texture.

  9. Reflecting telescope - Wikipedia

    en.wikipedia.org/wiki/Reflecting_telescope

    A convex secondary mirror is placed just to the side of the light entering the telescope, and positioned afocally so as to send parallel light on to the tertiary. The concave tertiary mirror is positioned exactly twice as far to the side of the entering beam as was the convex secondary, and its own radius of curvature distant from the secondary.