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Bokeh
In photography, bokeh ( or ; ) is the aesthetic quality of the blur produced in out-of-focus parts of an image, whether foreground or background or both. It is created by using a wide aperture lens. Some photographers incorrectly restrict use of the term bokeh to the appearance of bright spots in the out-of-focus area caused by circles of confusion. Bokeh has also been defined as "the way the lens renders out-of-focus points of light". Differences in lens aberrations and aperture shape cause very different bokeh effects. Some lens designs blur the image in a way that is pleasing to the eye, while others produce distracting or unpleasant blurring ("good" and "bad" bokeh, respectively). Photographers may deliberately use a shallow focus technique to create images with prominent out-of-focus regions, accentuating their lens's bokeh. Bokeh is often most visible around small background highlights, such as specular reflections and light sources, which is why it is ofte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shallow Focus
Shallow focus is a photographic and cinematographic technique incorporating a small depth of field. In shallow focus, one plane of the scene is in focus while the rest is out of focus. Shallow focus is typically used to emphasize one part of the image over another. Photographers sometimes refer to the aesthetic quality of the unfocused area(s) as bokeh. The opposite of shallow focus is deep focus, in which the entire image is in focus. Overview Shallow focus has become more popular in the 2000s and 2010s. It is also a means by which low budget filmmakers use to hide places that would require expensive props. It is often proclaimed by some to being a way to avoid the "video look." Extremely shallow focus – sometimes called ''bokeh porn'' – made its debut in cinematography in 2008 with the release of the Canon EOS 5D Mark II and the start of DSLR cinematography. Details The effect can be obtained by a larger aperture, a close viewpoint, a larger image sensor or a longer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Catadioptric System
A catadioptric optical system is one where refraction and Reflection (physics), reflection are combined in an optical system, usually via lens (optics), lenses (dioptrics) and curved mirrors (catoptrics). Catadioptric combinations are used in focusing systems such as searchlights, headlamps, early lighthouse focusing systems, optical telescopes, microscopes, and telephoto photographic lens, lenses. Other optical systems that use lenses and mirrors are also referred to as "catadioptric", such as surveillance catadioptric sensors. Early catadioptric systems Catadioptric combinations have been used for many early optical systems. In the 1820s, Augustin-Jean Fresnel developed several catadioptric lighthouse reflector versions of his Fresnel lens. Léon Foucault developed a catadioptric microscope in 1859 to counteract aberrations of using a lens to image objects at high power. In 1876 a French engineer, A. Mangin, invented what has come to be called the Mangin mirror, a concave glas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deep Focus
Deep focus is a photographic and cinematographic technique using a large depth of field. Depth of field is the front-to-back range of focus (optics), focus in an image, or how much of it appears sharp and clear. In deep focus, the foreground, middle ground, and background are all in focus. Deep focus is normally achieved by choosing a small aperture. Since the aperture of a camera determines how much light enters through the lens, achieving deep focus requires a bright scene or long-exposure photography, long exposure. A wide-angle lens also makes a larger portion of the image appear sharp. It is also possible to achieve the illusion of deep focus with optical tricks (split-focus diopter) or by compositing two or more images together using focus stacking. The opposite of deep focus is shallow focus, in which the plane of the image that is in focus is very shallow. For example, the foreground might be in focus while the middle-ground and background are out-of-focus. When avoiding ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meyer Optik Görlitz
Meyer Optik Görlitz (or Goerlitz; German), originally Hugo Meyer & Co., was a former optical company from Görlitz in Germany. It was founded in 1896 by optician Hugo Meyer (May 21, 1863 – March 1, 1905) and businessman Heinrich Schätze. The company got off to a successful start with the development of the wide-angle Aristostigmat lens and the subsequent acquisition of Optical Institute Schulze and Billerbeck, the manufacturers of “Euryplan lenses”, as they were called at the time. History A key business decision was made in 1920 when the company decided to work with former Zeiss developer Paul Rudolph, who was previously significantly involved in the success of the Protar, Planar and Tessar lenses. Rudolph also gave Meyer Optik access to his patent for the so-called Plasmat lenses, which at the time included one of the most powerful lenses in the world. In 1936, the company was renamed Optische und Feinmechanische Werke Hugo Meyer & Co and produced approximately 1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
F-number
An f-number is a measure of the light-gathering ability of an optical system such as a camera lens. It is calculated by dividing the system's focal length by the diameter of the entrance pupil ("clear aperture").Smith, Warren ''Modern Optical Engineering'', 4th Ed., 2007 McGraw-Hill Professional, p. 183. The f-number is also known as the focal ratio, f-ratio, or f-stop, and it is key in determining the depth of field, diffraction, and Exposure (photography), exposure of a photograph. The f-number is dimensionless number, dimensionless and is usually expressed using a lower-case Ƒ, hooked f with the format ''N'', where ''N'' is the f-number. The f-number is also known as the inverse relative aperture, because it is the Multiplicative inverse, inverse of the relative aperture, defined as the aperture diameter divided by focal length. The relative aperture indicates how much light can pass through the lens at a given focal length. A lower f-number means a larger relative apertur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Josefina With Bokeh
Josefina is a female name, a feminine form of Joseph (name), Joseph. It may refer to: *Josefina Passadori, Argentine writer *Josefina de la Torre, Spanish poet, novelist and opera singer *Josefina Klinger Zúñiga (born 1965), Colombian environmentalist *Josefina Lamberto, human rights activist. Her life was dedicated to the memory of her sister Maravillas Lamberto, raped and assassinated by the Francoists *Josefina Lopez, Chicana playwright *Josefina Pla, Spanish poet, playwright, art critic, painter and journalist *Josefina Ayerza, writer and a psychoanalyst *Josefina Deland, Swedish feminist *Josefina Wettergrund, Swedish writer *Josefina Robledo Gallego, Spanish classical guitarist *Josefina Tallado, Filipino politician Fiction *Josefina LaCosta, a fictional character in the Richard Sharpe series of novels by Bernard Cornwell. *Josefina, Gil Harris' fake girlfriend in the 2002 teen comedy ''The New Guy'' *Josefina Menendez, a fictional character in the 2012 first-person shoo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nikon
(, ; ) is a Japanese optics and photographic equipment manufacturer. Nikon's products include cameras, camera lenses, binoculars, microscopes, ophthalmic lenses, measurement instruments, rifle scopes, spotting scopes, and equipment related to Semiconductor device fabrication, semiconductor fabrication, such as Stepper, steppers used in the photolithography steps of such manufacturing. Nikon is the world's second largest manufacturer of such equipment. Since July 2024, Nikon has been headquartered in Nishi-Ōi, Shinagawa, Shinagawa, Tokyo where the plant has been located since 1918. The company is the eighth-largest chip equipment maker as reported in 2017. Also, it has diversified into new areas like 3D printers, 3D printing and regenerative medicine to compensate for the shrinking digital camera market. Among Nikon's many notable product lines are Nikkor imaging lenses (for Nikon F-mount, F-mount cameras, large format photography, photographic enlargers, and other applicatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Secondary Mirror
A secondary mirror (or secondary) is the second deflecting or focusing mirror element in a reflecting telescope. Light gathered by the primary mirror is directed towards a focal point typically past the location of the secondary. Secondary mirrors in the form of an optically flat ''diagonal mirror'' are used to re-direct the light path in designs such as Newtonian reflectors. They are also used to re-direct and extend the light path and modify the final image in designs such as Cassegrain reflectors. The secondary is typically suspended by X-shaped struts (sometimes called a "spider") in the path of light between the source and the primary, but can be mounted on other types of mounts or optical elements such as optical windows, or schmidt and meniscus corrector plates. Employing secondary mirrors in optical systems causes some image distortion due to the obstruction of the secondary itself, and distortion from the spider mounts, commonly seen as cross-shaped diffraction spike ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polygon
In geometry, a polygon () is a plane figure made up of line segments connected to form a closed polygonal chain. The segments of a closed polygonal chain are called its '' edges'' or ''sides''. The points where two edges meet are the polygon's '' vertices'' or ''corners''. An ''n''-gon is a polygon with ''n'' sides; for example, a triangle is a 3-gon. A simple polygon is one which does not intersect itself. More precisely, the only allowed intersections among the line segments that make up the polygon are the shared endpoints of consecutive segments in the polygonal chain. A simple polygon is the boundary of a region of the plane that is called a ''solid polygon''. The interior of a solid polygon is its ''body'', also known as a ''polygonal region'' or ''polygonal area''. In contexts where one is concerned only with simple and solid polygons, a ''polygon'' may refer only to a simple polygon or to a solid polygon. A polygonal chain may cross over itself, creating star polyg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spherical Aberration
In optics, spherical aberration (SA) is a type of aberration found in optical systems that have elements with spherical surfaces. This phenomenon commonly affects lenses and curved mirrors, as these components are often shaped in a spherical manner for ease of manufacturing. Light rays that strike a spherical surface off-centre are refracted or reflected more or less than those that strike close to the centre. This deviation reduces the quality of images produced by optical systems. The effect of spherical aberration was first identified in the 11th century by Ibn al-Haytham who discussed it in his work Kitāb al-Manāẓir. Overview A spherical lens has an aplanatic point (i.e., no spherical aberration) only at a lateral distance from the optical axis that equals the radius of the spherical surface divided by the index of refraction of the lens material. Spherical aberration makes the focus of telescopes and other instruments less than ideal. This is an important effect, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Circle Of Confusion
In optics, a circle of confusion (CoC) is an optical spot caused by a cone of light ray (optics), rays from a lens (optics), lens not coming to a perfect focus (optics), focus when imaging a Point source#Light, point source. It is also known as disk of confusion, circle of indistinctness, blur circle, or blur spot. In photography, the circle of confusion is used to determine the depth of field, the part of an image that is acceptably sharp. A standard value of CoC is often associated with each film format, image format, but the most appropriate value depends on visual acuity, viewing conditions, and the amount of enlargement. Usages in context include ''maximum permissible circle of confusion'', ''circle of confusion diameter limit'', and the ''circle of confusion criterion''. Real lenses defocus, do not focus all rays perfectly, so that even at best focus, a point is imaged as a spot rather than a point. The smallest such spot that a lens can produce is often referred to as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
