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  2. List of optics equations - Wikipedia

    en.wikipedia.org/wiki/List_of_optics_equations

    Image distance in a spherical mirror + = () Subscripts 1 and 2 refer to initial and final optical media respectively. These ratios are sometimes also used, following simply from other definitions of refractive index, wave phase velocity, and the luminal speed equation:

  3. Optics - Wikipedia

    en.wikipedia.org/wiki/Optics

    Euclid stated the principle of shortest trajectory of light, and considered multiple reflections on flat and spherical mirrors. Ptolemy , in his treatise Optics , held an extramission-intromission theory of vision: the rays (or flux) from the eye formed a cone, the vertex being within the eye, and the base defining the visual field.

  4. 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 ...

  5. 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.

  6. Geometrical optics - Wikipedia

    en.wikipedia.org/wiki/Geometrical_optics

    Geometrical optics, or ray optics, is a model of optics that describes light propagation in terms of rays.The ray in geometrical optics is an abstraction useful for approximating the paths along which light propagates under certain circumstances.

  7. Arago spot - Wikipedia

    en.wikipedia.org/wiki/Arago_spot

    Notation for calculating the wave amplitude at point P 1 from a spherical point source at P 0.. At the heart of Fresnel's wave theory is the Huygens–Fresnel principle, which states that every unobstructed point of a wavefront becomes the source of a secondary spherical wavelet and that the amplitude of the optical field E at a point on the screen is given by the superposition of all those ...

  8. Reflecting telescope - Wikipedia

    en.wikipedia.org/wiki/Reflecting_telescope

    A simple spherical mirror cannot bring light from a distant object to a common focus since the reflection of light rays striking the mirror near its edge do not converge with those that reflect from nearer the center of the mirror, a defect called spherical aberration.

  9. Newtonian telescope - Wikipedia

    en.wikipedia.org/wiki/Newtonian_telescope

    Newtonian telescope design. A Newtonian telescope is composed of a primary mirror or objective, usually parabolic in shape, and a smaller flat secondary mirror.The primary mirror makes it possible to collect light from the pointed region of the sky, while the secondary mirror redirects the light out of the optical axis at a right angle so it can be viewed with an eyepiece.