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Rectilinear Lens
In photography, a rectilinear lens is a photographic lens that yields images where straight features, such as the edges of walls of buildings, appear with straight lines, as opposed to being curved. In other words, it is a lens with little or no barrel or pincushion distortion. At particularly wide angles, however, the rectilinear perspective will cause objects to appear increasingly stretched and enlarged as they near the edge of the frame. These types of lenses are often used to create forced perspective effects. The most famous example is the Rapid Rectilinear Lens developed by John Henry Dallmeyer in 1866. It allowed distortionless photos to be taken quickly for the first time, and was a standard lens design for 60 years. As of 2020, the Laowa 9mm f/5.6 lens is the world's widest rectilinear lens for full frame cameras. The vast majority of video and still cameras use lenses that produce nearly rectilinear images. A popular alternative type of lens is a fisheye lens ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photography
Photography is the visual arts, art, application, and practice of creating images by recording light, either electronically by means of an image sensor, or chemically by means of a light-sensitive material such as photographic film. It is employed in many fields of science, manufacturing (e.g., photolithography), and business, as well as its more direct uses for art, film and video production, recreational purposes, hobby, and mass communication. A person who operates a camera to capture or take Photograph, photographs is called a photographer, while the captured image, also known as a photograph, is the result produced by the camera. Typically, a lens is used to focus (optics), focus the light reflected or emitted from objects into a real image on the light-sensitive surface inside a camera during a timed Exposure (photography), exposure. With an electronic image sensor, this produces an Charge-coupled device, electrical charge at each pixel, which is Image processing, electro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photographic Lens
A camera lens, photographic lens or photographic objective is an optical lens (optics), lens or assembly of lenses (compound lens) used in conjunction with a camera body and mechanism to Imaging, make images of objects either on photographic film or on other media capable of storing an image Photosensitivity, chemically or Image sensor, electronically. There is no major difference in principle between a lens used for a still camera, a video camera, a telescope, a microscope, or other apparatus, but the details of design and construction are different. A lens might be permanently fixed to a camera, or it might be interchangeable lens camera, interchangeable with lenses of different focal lengths, apertures, and other properties. While in principle a simple lens, simple convex lens will suffice, in practice a compound lens made up of a number of optical lens elements is required to correct (as much as possible) the many optical aberrations that arise. Some aberrations will be prese ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Curvilinear Perspective
Curvilinear perspective, also five-point perspective, is a graphical projection used to draw 3D objects on 2D surfaces, for which (straight) lines on the 3D object are projected to curves on the 2D surface that are typically not straight (hence the qualifier "curvilinear"). It was formally codified in 1968 by the artists and art historians André Barre and Albert Flocon in the book ''La Perspective curviligne'',Albert Flocon and André Barre, ''La Perspective curviligne'', Flammarion, Éditeur, Paris, 1968 which was translated into English in 1987 as ''Curvilinear Perspective: From Visual Space to the Constructed Image'' and published by the University of California Press.Albert Flocon and André Barre, ''Curvilinear Perspective: From Visual Space to the Constructed Image'', (Robert Hansen, translator), University of California Press, Berkeley and Los Angeles, California, 1987 Curvilinear perspective is sometimes colloquially called fisheye perspective, by analogy to a fisheye ... [...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] |
Forced Perspective
Forced perspective is a technique that employs optical illusion to make an object appear farther away, closer, larger or smaller than it actually is. It manipulates human visual perception through the use of scaled objects and the correlation between them and the vantage point of the spectator or camera. It has uses in photography, filmmaking and architecture. In filmmaking Forced perspective had been a feature of German silent films, and ''Citizen Kane'' revived the practice. Movies, especially B-movies in the 1950s and 1960s, were produced on limited budgets and often featured forced perspective shots. Forced perspective can be made more believable when environmental conditions obscure the difference in perspective. For example, the final scene of the famous movie ''Casablanca'' takes place at an airport in the middle of a storm, although the entire scene was shot in a studio. This was accomplished by using a painted backdrop of an aircraft, which was "serviced" by dwarfs stan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rapid Rectilinear
The Rapid Rectilinear also named Aplanat is a famous photographic lens design. The Rapid Rectilinear is a lens that is symmetrical about its aperture stop with four elements in two groups. It was introduced by John Henry Dallmeyer in 1866. The symmetry of the design greatly reduces radial distortion, improving on the Petzval lens. See also *Rectilinear lens In photography, a rectilinear lens is a photographic lens that yields images where straight features, such as the edges of walls of buildings, appear with straight lines, as opposed to being curved. In other words, it is a lens with little or n ... References * External links Rapid Rectilinear article Photographic lens designs {{photo-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Henry Dallmeyer
John Henry Dallmeyer (6 September 183030 December 1883), Anglo-German optician, was born at Loxten, Westphalia, the son of a landowner. On leaving school at the age of sixteen he was apprenticed to an Osnabrück optician, and in 1851 he came to London, where he obtained work with an optician, W Hewitt, who shortly afterwards, with his workmen, entered the employment of Andrew Ross, a lens and telescope manufacturer. Dallmeyer's position in this workshop appears to have been an unpleasant one, and led him to take, for a time, employment as French and German correspondent for a commercial firm. After a year he was, however, re-engaged by Ross as scientific adviser, and was entrusted with the testing and finishing of the highest class of optical apparatus. This appointment led to his marriage with Ross's second daughter, Hannah, and to the inheritance, at Ross's death (1859), of a third of his employer's large fortune and the telescope manufacturing portion of the business. Turning ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Full-frame DSLR
A full-frame DSLR is a digital single-lens reflex camera (DSLR) with a 35 mm image sensor format (). Historically, 35 mm was one of the standard film formats, alongside larger ones, such as medium format and large format. Many digital cameras, both compact and SLR models, use a smaller-than-35 mm frame as it is easier and cheaper to manufacture imaging sensors at a smaller size. Historically, the earliest digital SLR models, such as the Nikon NASA F4 or Kodak DCS 100, also used a smaller sensor. Kodak states that 35 mm film (note: in " Academy format", 21.0 mm × 15.2 mm) has the equivalent of 6K horizontal resolution, according to a senior vice president of IMAX. This equates to 10K horizontal resolution in full-frame size. Use of 35 mm film-camera lenses If the lens mounts are compatible, many lenses, including manual-focus models, designed for 35 mm cameras can be mounted on DSLR cameras. When a lens designed for a full-frame camera, wheth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fisheye Lens
A fisheye lens is an ultra wide angle lens, ultra wide-angle lens that produces strong Distortion (optics), visual distortion intended to create a wide panorama, panoramic or Sphere#Hemisphere, hemispherical image. Fisheye lenses achieve extremely wide angle of view, angles of view, well beyond any rectilinear lens. Instead of producing images with straight lines of perspective (rectilinear lens, rectilinear images), fisheye lenses use a special mapping ("distortion"; for example: Lambert azimuthal equal-area projection, equisolid angle, see below), which gives images a characteristic convex non-rectilinear appearance. The term ''fisheye'' was coined in 1906 by American physicist and inventor Robert W. Wood based on how a fish would see an ultrawide hemispherical view from beneath the water (a phenomenon known as Snell's window). Their first practical use was in the 1920s for use in meteorology to study cloud formation giving them the name ''whole-sky lenses''. The angle of view ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wide-angle Lens
In photography and cinematography, a wide-angle lens is a Photographic lens, lens covering a large angle of view. Conversely, its focal length is substantially smaller than that of a normal lens for a given film plane. This type of lens allows more of the Scene (perception), scene to be included in the photograph, which is useful in architectural, interior, and landscape photography where the photographer may not be able to move farther from the scene to photograph it. Another use is where the photographer wishes to emphasize the difference in size or distance between objects in the foreground and the background; nearby objects appear very large and objects at a moderate distance appear small and far away. This exaggeration of relative size can be used to make foreground objects more prominent and striking, while capturing expansive backgrounds. A wide-angle lens is also one that projects a substantially larger image circle than would be typical for a standard design lens of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rectilinear Grid
A regular grid is a tessellation of ''n''-dimensional Euclidean space by congruent parallelotopes (e.g. bricks). Its opposite is irregular grid. Grids of this type appear on graph paper and may be used in finite element analysis, finite volume methods, finite difference methods, and in general for discretization of parameter spaces. Since the derivatives of field variables can be conveniently expressed as finite differences, structured grids mainly appear in finite difference methods. Unstructured grids offer more flexibility than structured grids and hence are very useful in finite element and finite volume methods. Each cell in the grid can be addressed by index (i, j) in two dimensions or (i, j, k) in three dimensions, and each vertex has coordinates (i\cdot dx, j\cdot dy) in 2D or (i\cdot dx, j\cdot dy, k\cdot dz) in 3D for some real numbers ''dx'', ''dy'', and ''dz'' representing the grid spacing. Related grids A Cartesian grid is a special case where the elements are un ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
