Diaphragm (optics)
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Diaphragm (optics)
In optics, a diaphragm is a thin opaque structure with an opening (aperture) at its center. The role of the diaphragm is to ''stop'' the passage of light, except for the light passing through the ''aperture''. Thus it is also called a stop (an aperture stop, if it limits the brightness of light reaching the focal plane, or a field stop or flare stop for other uses of diaphragms in lenses). The diaphragm is placed in the light path of a lens or objective, and the size of the aperture regulates the amount of light that passes through the lens. The centre of the diaphragm's aperture coincides with the optical axis of the lens system. Most modern cameras use a type of adjustable diaphragm known as an iris diaphragm, and often referred to simply as an iris. See the articles on aperture and f-number for the photographic effect and system of quantification of varying the opening in the diaphragm. Iris diaphragms versus other types A natural optical system that has a diaphragm an ...
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Circle Of Confusion
In optics, a circle of confusion (CoC) is an optical spot caused by a cone of light rays from a lens not coming to a perfect focus when imaging a 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 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 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 the circle of least confusion. Two uses Two important uses of this term and concept n ...
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Daniele Barbaro
Daniele Matteo Alvise Barbaro (also Barbarus) (8 February 1514 – 13 April 1570) was an Italian cleric and diplomat. He was also an architect, writer on architecture, and translator of, and commentator on, Vitruvius. Barbaro's fame is chiefly due to his vast output in the arts, letters, and mathematics. A cultured humanist, he was a friend and admirer of Torquato Tasso, a patron of Andrea Palladio, and a student of Pietro Bembo. Francesco Sansovino considered Daniele to be one of the three best Venetian architects, along with Palladio and Francesco's father Jacopo. Biography He was born in Venice, the son of Francesco di Daniele Barbaro and Elena Pisani, daughter of the banker Alvise Pisani and Cecilia Giustinian. Barbaro studied philosophy, mathematics, and optics at the University of Padua. He has been credited with the design of the university's botanical garden. Barbaro served the Republic of Venice as ambassador to the court of Edward VI in London and as representat ...
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Depth Of Field
The depth of field (DOF) is the distance between the nearest and the furthest objects that are in acceptably sharp focus in an image captured with a camera. Factors affecting depth of field For cameras that can only focus on one object distance at a time, depth of field is the distance between the nearest and the farthest objects that are in acceptably sharp focus. "Acceptably sharp focus" is defined using a property called the "circle of confusion". The depth of field can be determined by focal length, distance to subject, the acceptable circle of confusion size, and aperture. Limitations of depth of field can sometimes be overcome with various techniques and equipment. The approximate depth of field can be given by: : \text \approx \frac for a given circle of confusion (c), focal length (f), f-number (N), and distance to subject (u). As distance or the size of the acceptable circle of confusion increases, the depth of field increases; however, increasing the size of ...
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ND Filter
In photography and optics, a neutral-density filter, or ND filter, is a filter that reduces or modifies the intensity of all wavelengths, or colors, of light equally, giving no changes in hue of color rendition. It can be a colorless (clear) or grey filter, and is denoted by Wratten number 96. The purpose of a standard photographic neutral-density filter is to reduce the amount of light entering the lens. Doing so allows the photographer to select combinations of aperture, exposure time and sensor sensitivity that would otherwise produce overexposed pictures. This is done to achieve effects such as a shallower depth of field or motion blur of a subject in a wider range of situations and atmospheric conditions. For example, one might wish to photograph a waterfall at a slow shutter speed to create a deliberate motion-blur effect. The photographer might determine that to obtain the desired effect, a shutter speed of ten seconds was needed. On a very bright day, there might be so ...
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Point-and-shoot Camera
A point-and-shoot camera, also known as a compact camera and sometimes abbreviated to P&S, is a still camera designed primarily for simple operation. Most use focus free lenses or autofocus for focusing, automatic systems for setting the exposure options, and have flash units built in. They are popular for vernacular photography by people who do not consider themselves photographers but want easy-to-use cameras for snapshots of vacations, parties, reunions and other events. Most of these compact cameras use small 1/2.3" image sensors, but since 2008, a few non-interchangeable lens compact cameras use a larger sensor such as 1" and even APS-C, such as the Fujifilm X100 series, or full frame format such as the Sony Cyber-shot DSC-RX1 series. They prioritize intelligent Auto, but some high end point-and-shoot cameras have PASM (program, aperture priority, shutter priority, and manual modes) on the mode dial, raw image format, and hot shoe. None have interchangeable lenses, but s ...
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Fujinon XF 56mm F1
Fujinon is a brand of optical lenses made by Fuji Photo Film Co., Ltd, now known as Fujifilm. Fujifilm's Fujinon lenses have been used by professional photographers and broadcast stations as well as cinematography. Fujifilm started manufacture of optical glass in its Odawara Factory in Japan in 1940, which was the start of the Fujinon brand. They were proud of their use of expensive Platinum crucibles to get the purest glass achievable at the time. Fujifilm also pioneered Electron Beam Coating (EBC) which according to Fujifilm, represented a new high in lens precision and performance. The EBC process was significantly different from other coating processes by the number of coating, the thinness of the coating, and the materials used for coating. Fujifilm claimed they were able to have as much as 14 layers of coating and used materials such as zirconium oxide, and cerium fluoride, which could not be used for coating in the conventional coating process. The first lens to offer ...
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Smooth Trans Focus
The Smooth Trans Focus (STF) technology in photographic lenses uses an apodization filter to realize notably smooth bokeh with rounded out-of-focus highlights in both the foreground and background. This is accomplished by utilizing a concave neutral-gray tinted lens element next to the aperture blades as apodization filter, a technology originally invented (and patented) by Minolta in the 1980s, and first implemented in a commercially available lens in 1999. In contrast to soft focus lenses, STF lenses render a perfectly sharp image in the focus plane. Lenses featuring ''Smooth Trans Focus'' technology: * Minolta STF 135mm F2.8 4.5(introduced 1999) * Sony α STF 135mm F2.8 4.5(SAL-135F28) (introduced 2006) * Sony FE 100mm F2.8 STF GM OSS (SEL-100F28GM) (introduced 2017) See also * STF function (an emulation of the effect in the Minolta Maxxum 7) * Fujinon XF 56mm F1.2 R APD (a similar lens introduced by Fujifilm in 2014) * Venus Optics Laowa 105mm f/2 Smooth Trans Focus (a ...
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Sony
, commonly stylized as SONY, is a Japanese multinational conglomerate corporation headquartered in Minato, Tokyo, Japan. As a major technology company, it operates as one of the world's largest manufacturers of consumer and professional electronic products, the largest video game console company and the largest video game publisher. Through Sony Entertainment Inc, it is one of the largest music companies (largest music publisher and second largest record label) and the third largest film studio, making it one of the most comprehensive media companies. It is the largest technology and media conglomerate in Japan. It is also recognized as the most cash-rich Japanese company, with net cash reserves of ¥2 trillion. Sony, with its 55 percent market share in the image sensor market, is the largest manufacturer of image sensors, the second largest camera manufacturer, and is among the semiconductor sales leaders. It is the world's largest player in the premium TV market for ...
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Minolta
was a Japanese manufacturer of cameras, camera accessories, photocopiers, fax machines, and laser printers. Minolta Co., Ltd., which is also known simply as Minolta, was founded in Osaka, Japan, in 1928 as . It made the first integrated autofocus 35 mm SLR camera system. In 1931, the company adopted its final name, an acronym for "Mechanism, Instruments, Optics, and Lenses by Tashima". In 2003, Minolta merged with Konica to form Konica Minolta. On 19 January 2006, Konica Minolta announced that it was leaving the camera and photo business, and that it would sell a portion of its SLR camera business to Sony as part of its move to pull completely out of the business of selling cameras and photographic film. History Milestones *1928: establishes Nichi-Doku Shashinki Shōten ("Japanese-German photo company," the precursor of Minolta Co., Ltd.). *1929: Marketed the company's first camera, the "Nifcarette" (ニフカレッテ). *1937: The Minolta Flex is Japan's second twin- ...
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Apodization Filter
In signal processing, apodization (from Greek "removing the foot") is the modification of the shape of a mathematical function. The function may represent an electrical signal, an optical transmission or a mechanical structure. In optics, it is primarily used to remove Airy disks caused by diffraction around an intensity peak, improving the focus. Apodization in electronics Apodization in signal processing The term apodization is used frequently in publications on Fourier-transform infrared (FTIR) signal processing. An example of apodization is the use of the Hann window in the fast Fourier transform analyzer to smooth the discontinuities at the beginning and end of the sampled time record. Apodization in digital audio An apodizing filter can be used in digital audio processing instead of the more common brickwall filters, in order to avoid the pre-ringing that the latter introduces. Apodization in mass spectrometry During oscillation within an Orbitrap, ion trans ...
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