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  2. Vergence (optics) - Wikipedia

    en.wikipedia.org/wiki/Vergence_(optics)

    In geometrical optics, vergence describes the curvature of optical wavefronts. [1] Vergence is defined as. where n is the medium's refractive index and r is the distance from the point source to the wavefront. Vergence is measured in units of dioptres (D) which are equivalent to m −1. [1] This describes the vergence in terms of optical power.

  3. Point spread function - Wikipedia

    en.wikipedia.org/wiki/Point_spread_function

    The point spread function ( PSF) describes the response of a focused optical imaging system to a point source or point object. A more general term for the PSF is the system's impulse response; the PSF is the impulse response or impulse response function (IRF) of a focused optical imaging system. The PSF in many contexts can be thought of as the ...

  4. Weierstrass M-test - Wikipedia

    en.wikipedia.org/wiki/Weierstrass_M-test

    Weierstrass M-test. In mathematics, the Weierstrass M-test is a test for determining whether an infinite series of functions converges uniformly and absolutely. It applies to series whose terms are bounded functions with real or complex values, and is analogous to the comparison test for determining the convergence of series of real or complex ...

  5. Optical resolution - Wikipedia

    en.wikipedia.org/wiki/Optical_resolution

    This ability is expressed by the Optical Transfer Function which describes the spatial (angular) variation of the light signal as a function of spatial (angular) frequency. When the image is projected onto a flat plane, such as photographic film or a solid state detector, spatial frequency is the preferred domain, but when the image is referred ...

  6. Diffraction-limited system - Wikipedia

    en.wikipedia.org/wiki/Diffraction-limited_system

    An optical instrument is said to be diffraction-limited if it has reached this limit of resolution performance. Other factors may affect an optical system's performance, such as lens imperfections or aberrations, but these are caused by errors in the manufacture or calculation of a lens, whereas the diffraction limit is the maximum resolution ...

  7. Fermat's principle - Wikipedia

    en.wikipedia.org/wiki/Fermat's_principle

    If we seek the required value of x, we find that the angles α and β satisfy Snell's law. Fermat's principle, also known as the principle of least time, is the link between ray optics and wave optics. Fermat's principle states that the path taken by a ray between two given points is the path that can be traveled in the least time.

  8. Köhler illumination - Wikipedia

    en.wikipedia.org/wiki/Köhler_illumination

    Köhler illumination is a method of specimen illumination used for transmitted and reflected light (trans- and epi-illuminated) optical microscopy. Köhler illumination acts to generate an even illumination of the sample and ensures that an image of the illumination source (for example a halogen lamp filament) is not visible in the resulting image.

  9. Test functions for optimization - Wikipedia

    en.wikipedia.org/wiki/Test_functions_for...

    Convergence rate. Precision. Robustness. General performance. Here some test functions are presented with the aim of giving an idea about the different situations that optimization algorithms have to face when coping with these kinds of problems. In the first part, some objective functions for single-objective optimization cases are presented.