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In geometric optics, distortion is a deviation from rectilinear projection; a projection in which straight lines in a scene remain straight in an image.It is a form of optical aberration that may be distinguished from other aberrations such as spherical aberration, coma, chromatic aberration, field curvature, and astigmatism in a sense that these impact the image sharpness without changing an ...
In optics, aberration is a property of optical systems, such as lenses, that causes light to be spread out over some region of space rather than focused to a point. [1] Aberrations cause the image formed by a lens to be blurred or distorted, with the nature of the distortion depending on the type of aberration.
In optics, chromatic aberration (CA), also called chromatic distortion, color aberration, color fringing, or purple fringing, is a failure of a lens to focus all colors to the same point. [ 1 ] [ 2 ] It is caused by dispersion : the refractive index of the lens elements varies with the wavelength of light .
A fisheye lens is an ultra wide-angle lens that produces strong visual distortion intended to create a wide panoramic or hemispherical image. [4] [5]: 145 Fisheye lenses achieve extremely wide angles of view, well beyond any rectilinear lens.
Radio telescopes are frequently diffraction-limited, because the wavelengths they use (from millimeters to meters) are so long that the atmospheric distortion is negligible. Space-based telescopes (such as Hubble, or a number of non-optical telescopes) always work at their diffraction limit, if their design is free of optical aberration.
Fig. 2b: An instrumental pincushion distortion of = leads to an almost complete elimination of the globe effect. The image of an afocal optical instrument is distortion-free if the f-tan theta condition, also known as tangent condition and first defined by Bow and Sutton in 1861, is satisfied: [4] = .
An optical system with astigmatism is one where rays that propagate in two perpendicular planes have different foci. If an optical system with astigmatism is used to form an image of a cross, the vertical and horizontal lines will be in sharp focus at two different
The degree of image blurring for a given amount of focus shift depends inversely on the lens f-number. Low f-numbers, such as f /1.4 to f / 2.8, are very sensitive to defocus and have very shallow depths of focus. High f-numbers, in the f / 16 to f / 32 range, are highly tolerant of defocus, and consequently have large depths of focus.