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Apodization
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 brick-wall filters, in order to reduce the pre- and post- ringing that the latter introduces. Apodization in mass spectrometry During oscillation within an Orbit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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] |
Window Function
In signal processing and statistics, a window function (also known as an apodization function or tapering function) is a mathematical function that is zero-valued outside of some chosen interval. Typically, window functions are symmetric around the middle of the interval, approach a maximum in the middle, and taper away from the middle. Mathematically, when another function or waveform/data-sequence is "multiplied" by a window function, the product is also zero-valued outside the interval: all that is left is the part where they overlap, the "view through the window". Equivalently, and in actual practice, the segment of data within the window is first isolated, and then only that data is multiplied by the window function values. Thus, tapering, not segmentation, is the main purpose of window functions. The reasons for examining segments of a longer function include detection of transient events and time-averaging of frequency spectra. The duration of the segments is determine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Depth-of-field Bracketing
In photography, bracketing is the general technique of taking several shots of the same subject using different camera settings, typically with the aim of combining the images in postprocessing. Bracketing is useful and often recommended in situations that make it difficult to obtain a satisfactory image with a single shot, especially when a small variation in exposure parameters has a comparatively large effect on the resulting image. Given the time it takes to accomplish multiple shots, it is typically, but not always, used for static subjects. Autobracketing is a feature of many modern cameras. When set, it will automatically take several bracketed shots, rather than the photographer altering the settings by hand between each shot. Types of bracketing Exposure bracketing Image:StLouisArchMultExpEV-4.72.JPG, –4 stops Image:StLouisArchMultExpEV-1.82.JPG, –2 stops Image:StLouisArchMultExpEV+1.51.JPG, +2 stops Image:StLouisArchMultExpEV+4.09.JPG, +4 stops Without furth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fourier-transform Infrared Spectroscopy
Fourier transform infrared spectroscopy (FTIR) is a technique used to obtain an infrared spectrum of absorption or emission of a solid, liquid, or gas. An FTIR spectrometer simultaneously collects high-resolution spectral data over a wide spectral range. This confers a significant advantage over a dispersive spectrometer, which measures intensity over a narrow range of wavelengths at a time. The term ''Fourier transform infrared spectroscopy'' originates from the fact that a Fourier transform (a mathematical process) is required to convert the raw data into the actual spectrum. Conceptual introduction The goal of absorption spectroscopy techniques (FTIR, ultraviolet-visible ("UV-vis") spectroscopy, etc.) is to measure how much light a sample absorbs at each wavelength. The most straightforward way to do this, the "dispersive spectroscopy" technique, is to shine a monochromatic light beam at a sample, measure how much of the light is absorbed, and repeat for each different ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 diaphra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diffraction Disc Calculated
Diffraction is the deviation of waves from straight-line propagation without any change in their energy due to an obstacle or through an aperture. The diffracting object or aperture effectively becomes a secondary source of the propagating wave. Diffraction is the same physical effect as interference, but interference is typically applied to superposition of a few waves and the term diffraction is used when many waves are superposed. Italian scientist Francesco Maria Grimaldi coined the word ''diffraction'' and was the first to record accurate observations of the phenomenon in 1660. In classical physics, the diffraction phenomenon is described by the Huygens–Fresnel principle that treats each point in a propagating wavefront as a collection of individual spherical wavelets. The characteristic pattern is most pronounced when a wave from a coherent source (such as a laser) encounters a slit/aperture that is comparable in size to its wavelength, as shown in the inserted image. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Medical Ultrasonography
Medical ultrasound includes Medical diagnosis, diagnostic techniques (mainly medical imaging, imaging) using ultrasound, as well as therapeutic ultrasound, therapeutic applications of ultrasound. In diagnosis, it is used to create an image of internal body structures such as tendons, muscles, joints, blood vessels, and internal organs, to measure some characteristics (e.g., distances and velocities) or to generate an informative audible sound. The usage of ultrasound to produce visual images for medicine is called medical ultrasonography or simply sonography, or echography. The practice of examining pregnant women using ultrasound is called obstetric ultrasonography, and was an early development of clinical ultrasonography. The machine used is called an ultrasound machine, a sonograph or an echograph. The visual image formed using this technique is called an ultrasonogram, a sonogram or an echogram. Ultrasound is composed of sound waves with frequency, frequencies greater than ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sony E-mount
The E-mount is a lens mount designed by Sony for their NEX ("New E-mount eXperience") and Sony ILCE camera, ILCE series of camcorders and mirrorless interchangeable lens camera, mirrorless cameras. The E-mount supplements Sony's Sony α, α mount, allowing the company to develop more compact imaging devices while maintaining vignetting with 35mm sensors. E-mount achieves this by: * Minimising mechanical complexity, removing mechanical aperture and Focus (optics), focus drive. * Shortening the flange focal distance to 18 mm compared with earlier offerings from Sony which used 44.5 mm. * Reducing the radius of the flange. * Relying on software to correct vignetting The short flange focal distance prohibits the use of an optical viewfinder, as a mirror box mechanism cannot be included in this reduced distance. Therefore, all E-mount cameras use an electronic viewfinder. History Initially, E-mount was implemented on the Sony α Sony NEX-3, NEX-3 and Sony NEX-5, NEX-5 consume ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sony
is a Japanese multinational conglomerate (company), conglomerate headquartered at Sony City in Minato, Tokyo, Japan. The Sony Group encompasses various businesses, including Sony Corporation (electronics), Sony Semiconductor Solutions (imaging and sensing), Sony Entertainment (including Sony Pictures and Sony Music Group), Sony Interactive Entertainment (video games), Sony Financial Group, and others. Sony was founded in 1946 as by Masaru Ibuka and Akio Morita. In 1958, the company adopted the name Initially an electronics firm, it gained early recognition for products such as the TR-55 transistor radio and the CV-2000 home video tape recorder, contributing significantly to Japan's Japanese economic miracle, post-war economic recovery. After Ibuka's retirement in the 1970s, Morita served as chairman until 1994, overseeing Sony's rise as a global brand recognized for innovation in consumer electronics. Landmark products included the Trinitron color television, the Walkma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 many 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fujifilm
, trading as , or simply Fuji, is a Japanese Multinational corporation, multinational Conglomerate (company), conglomerate headquartered in Tokyo, Japan, operating in the areas of photography, optics, Office supplies, office and Biomedical engineering, medical electronics, biotechnology, and Chemical substance, chemicals. The company started as a manufacturer of photographic films, which it still produces. Fujifilm products include document solutions, medical imaging and diagnostics equipment, cosmetics, Medication, pharmaceutical drugs, regenerative medicine, stem cells, Contract manufacturing organization, biologics manufacturing, magnetic tape data storage, Optical coating, optical films for flat-panel displays, Optical instrument, optical devices, photocopiers, printers, digital cameras, Color photography, color films, color paper, Photographic processing, photofinishing and graphic arts equipment and materials. Fujifilm is part of the Sumitomo Mitsui Financial Group financia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
STF Function
Autobracketing is a feature of some more advanced cameras, whether film or digital cameras, particularly single-lens reflex cameras, where the camera will take several successive shots (often three) with slightly different settings. The images may be automatically combined, for example into one high-dynamic-range image, or they may be stored separately so the best-looking pictures can be picked later from the batch. When the photographer achieves the same result by changing the camera settings between each shot, this is simply called bracketing. Parameter altered The bracketing is typically for one specific parameter: Exposure Exposure autobracketing (often abbreviated to ''AEB'' for ''automatic exposure bracketing'' or ''BR'' for ''Bracketing'') is the most common form. In this, the camera is set to capture the same image several times with different exposure settings, both over-exposed and under-exposed (lighter and darker) compared to the current setting on the camera, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
