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Aberration In Optical Systems
In optics, aberration is a property of optical systems, such as Lens (optics), lenses and mirrors, that causes the ''image'' created by the optical system to not be a faithful reproduction of the ''object'' being observed. Aberrations cause the image formed by a lens to be blurred, distorted in shape or have color fringing or other effects not seen in the object, with the nature of the distortion depending on the type of aberration. Aberration can be defined as a departure of the performance of an optical system from the predictions of paraxial optics. In an imaging system, it occurs when light from one point of an object does not converge into (or does not diverge from) a single point after transmission through the system. Aberrations occur because the simple paraxial theory is not a completely accurate model of the effect of an optical system on light, rather than due to flaws in the optical elements. An image-forming optical system with aberration will produce an image which i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lens Chromatic Aberration
A lens is a transmissive optics, optical device that focuses or disperses a light beam by means of refraction. A simple lens consists of a single piece of transparent material, while a #Compound lenses, compound lens consists of several simple lenses (''elements''), usually arranged along a common Optical axis, axis. Lenses are made from materials such as glass or plastic and are Grinding (abrasive cutting), ground, Polishing, polished, or Molding (process), molded to the required shape. A lens can focus light to form an image, unlike a Prism (optics), prism, which refracts light without focusing. Devices that similarly focus or disperse waves and radiation other than visible light are also called "lenses", such as microwave lenses, electron lenses, acoustic lenses, or explosive lenses. Lenses are used in various imaging devices such as telescopes, binoculars, and cameras. They are also used as visual aids in glasses to correct defects of vision such as Near-sightedness, myopia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Defocus Aberration
In optics, defocus is the aberration in which an image is simply out of focus. This aberration is familiar to anyone who has used a camera, videocamera, microscope, telescope, or binoculars. Optically, defocus refers to a translation of the focus along the optical axis away from the detection surface. In general, defocus reduces the sharpness and contrast of the image. What should be sharp, high-contrast edges in a scene become gradual transitions. Fine detail in the scene is blurred or even becomes invisible. Nearly all image-forming optical devices incorporate some form of focus adjustment to minimize defocus and maximize image quality. In optics and photography The degree of image blurring for a given amount of focus shift depends inversely on the lens f-number. Low f-numbers, such as to 2.8, are very sensitive to defocus and have very shallow depths of focus. High f-numbers, in the 16 to 32 range, are highly tolerant of defocus, and consequently have large depths ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ernst Abbe
Ernst Karl Abbe (23 January 1840 – 14 January 1905) was a German businessman, optical engineer, physicist, and social reformer. Together with Otto Schott and Carl Zeiss, he developed numerous optical instruments. He was also a co-owner of Carl Zeiss AG, a German manufacturer of scientific microscopes, astronomical telescopes, planetariums, and other advanced optical systems. Personal life Abbe was born 23 January 1840 in Eisenach, Saxe-Weimar-Eisenach, to Georg Adam Abbe and Elisabeth Christina Barchfeldt. He came from a humble home – his father was a foreman in a spinnery. Supported by his father's employer, Abbe was able to attend secondary school and to obtain the general qualification for university entrance with fairly good grades, at the Eisenach Gymnasium, which he graduated from in 1857. By the time he left school, his scientific talent and his strong will had already become obvious. Thus, in spite of the family's strained financial situation, his father decide ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
James Clerk Maxwell
James Clerk Maxwell (13 June 1831 – 5 November 1879) was a Scottish physicist and mathematician who was responsible for the classical theory of electromagnetic radiation, which was the first theory to describe electricity, magnetism and light as different manifestations of the same phenomenon. Maxwell's equations for electromagnetism achieved the Unification (physics)#Unification of magnetism, electricity, light and related radiation, second great unification in physics, where Unification (physics)#Unification of gravity and astronomy, the first one had been realised by Isaac Newton. Maxwell was also key in the creation of statistical mechanics. With the publication of "A Dynamical Theory of the Electromagnetic Field" in 1865, Maxwell demonstrated that electric force, electric and magnetic fields travel through space as waves moving at the speed of light. He proposed that light is an undulation in the same medium that is the cause of electric and magnetic phenomena. (Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Focal Plane
In Gaussian optics, the cardinal points consist of three pairs of points located on the optical axis of a rotationally symmetric, focal, optical system. These are the '' focal points'', the principal points, and the nodal points; there are two of each. For ''ideal'' systems, the basic imaging properties such as image size, location, and orientation are completely determined by the locations of the cardinal points. For simple cases where the medium on both sides of an optical system is air or vacuum four cardinal points are sufficient: the two focal points and either the principal points or the nodal points. The only ideal system that has been achieved in practice is a plane mirror, however the cardinal points are widely used to the behavior of real optical systems. Cardinal points provide a way to analytically simplify an optical system with many components, allowing the imaging characteristics of the system to be approximately determined with simple calculations. Explanation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Focal Length
The focal length of an Optics, optical system is a measure of how strongly the system converges or diverges light; it is the Multiplicative inverse, inverse of the system's optical power. A positive focal length indicates that a system Convergence (optics), converges light, while a negative focal length indicates that the system Divergence (optics), diverges light. A system with a shorter focal length bends the Ray (optics), rays more sharply, bringing them to a focus in a shorter distance or diverging them more quickly. For the special case of a thin lens in air, a positive focal length is the distance over which initially Collimated beam, collimated (parallel) rays are brought to a Focus (optics), focus, or alternatively a negative focal length indicates how far in front of the lens a point source must be located to form a collimated beam. For more general optical systems, the focal length has no intuitive meaning; it is simply the inverse of the system's optical power. In mos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carl Friedrich Gauss
Johann Carl Friedrich Gauss (; ; ; 30 April 177723 February 1855) was a German mathematician, astronomer, geodesist, and physicist, who contributed to many fields in mathematics and science. He was director of the Göttingen Observatory and professor of astronomy from 1807 until his death in 1855. While studying at the University of Göttingen, he propounded several mathematical theorems. As an independent scholar, he wrote the masterpieces '' Disquisitiones Arithmeticae'' and ''Theoria motus corporum coelestium''. Gauss produced the second and third complete proofs of the fundamental theorem of algebra. In number theory, he made numerous contributions, such as the composition law, the law of quadratic reciprocity and the Fermat polygonal number theorem. He also contributed to the theory of binary and ternary quadratic forms, the construction of the heptadecagon, and the theory of hypergeometric series. Due to Gauss' extensive and fundamental contributions to science ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tilt (optics)
In optics, tilt is a deviation in the direction a beam of light propagates. Overview Tilt quantifies the average slope in both the X and Y directions of a wavefront or phase profile across the pupil of an optical system. In conjunction with piston (the first Zernike polynomial term), X and Y tilt can be modeled using the second and third Zernike polynomials: :X-Tilt: a_1 \rho \cos(\theta) :Y-Tilt: a_2 \rho \sin(\theta) where \rho is the normalized radius with 0 \le \rho \le 1 and \theta is the azimuthal angle with 0 \le \theta \le 2\pi. The a_1 and a_2 coefficients are typically expressed as a fraction of a chosen wavelength of light. Piston and tilt are not actually true optical aberrations, as they do not represent or model curvature in the wavefront. Defocus is the lowest order true optical aberration. If piston and tilt are subtracted from an otherwise perfect wavefront, a perfect, aberration-free image is formed. Rapid optical tilts in both X and Y directions are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Piston (optics)
In optics, piston is the mean value of a wavefront or phase profile across the pupil of an optical system. The piston coefficient is typically expressed in wavelengths of light at a particular wavelength. Its main use is in curve-fitting wavefronts with Cartesian polynomials or Zernike polynomials. However, similar to a real engine piston moving up and down in its cylinder, optical piston values can be changed to bias the wavefront phase mean value as desired. As phase values can only vary from zero to 2π, then repeat in either direction (termed phase wrapping), changing the piston coefficient changes the zero phase value contour locations across the wavefront. This property is critical to the operation of phase-measuring interferometers, which give not only the magnitude but also the sign ( convexity or concavity) of a wavefront under test. Piston is physically created in the interferometer by piezoelectric actuators that translate the Fizeau interferometer reference ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Image Distortion
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 object shape or structure in the image (e.g., a straight line in an object is still a straight line in the image although the image sharpness may be degraded by the mentioned aberrations) while distortion can change the object structure in the image (so named as distortion). Radial distortion Although distortion can be irregular or follow many patterns, the most commonly encountered distortions are radially symmetric, or approximately so, arising from the symmetry of a photographic lens. These ''radial distortions'' can usually be classified as either ''barrel'' distortions or '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Field Curvature
Petzval field curvature, named for Joseph Petzval, describes the optical aberration in which a flat object normal to the optical axis (or a non-flat object past the hyperfocal distance) cannot be brought properly into focus on a flat image plane. Field curvature can be corrected with the use of a ''Field flattener lens, field flattener'', designs can also incorporate a curved focal plane like in the case of the human eye in order to improve image quality at the focal surface. Analysis Consider an "ideal" single-element lens system for which all planar wave fronts are focused to a point at distance ''f'' from the lens. Placing this lens the distance ''f'' from a flat image sensor, image points near the optical axis will be in perfect focus, but rays off axis will come into focus before the image sensor, dropping off by the cosine of the angle they make with the optical axis. This is less of a problem when the imaging surface is spherical, as in the human eye. Most current photog ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
