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Projection Screen
A projection screen is an installation consisting of a surface and a support structure used for displaying a projected image for the view of an audience. Projection screens may be permanently installed, as in a movie theater; painted on the wall; or portable with tripod or floor rising models as in a conference room or other non-dedicated viewing space. Another popular type of portable screens are inflatable screens for outdoor movie screening ( open-air cinema). Uniformly white or grey screens are used almost exclusively as to avoid any discoloration to the image, while the most desired brightness of the screen depends on a number of variables, such as the ambient light level and the luminous power of the image source. Flat or curved screens may be used depending on the optics used to project the image and the desired geometrical accuracy of the image production, flat screens being the more common of the two. Screens can be further designed for front or back projection, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sala De Cine
Sala or SALA may refer to: Places Europe * Sala, the historical name of the river IJssel and home of the Salii Franks * Sala (Estonian island), one of the Uhtju islands * Sala Baganza, a municipality in Emilia-Romagna, Italy * Sala Bolognese, a municipality in Emilia-Romagna, Italy * Sala Consilina, a municipality in Campania, Italy * Sala Municipality, Latvia, a municipality in Latvia * Sala, Sala Parish, a village in Latvia, an administrative centre of Sala municipality * Šaľa, Slovakia, a city in Slovakia * Sala Municipality, Sweden, a municipality in Sweden * Sala, Sweden, a city in Sweden, seat of Sala Municipality * Sala Parish (other), parishes (''socken'') in Sweden Africa * Salé ( ber, Sala, link=no), Morocco * Chellah, Sala, an ancient city at Rabat#Ancient Sala, Rabat, Morocco * Sala, Houet, a village in Satiri Department, Houet Province, Burkina Faso * Sala, Ziro, a village in Ziro Province, Burkina Faso * Sala Colonia, a Phoenician and Roman colony whose ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Slide Projector
A slide projector is an opto-mechanical device for showing photographic slides. 35 mm slide projectors, direct descendants of the larger-format magic lantern, first came into widespread use during the 1950s as a form of occasional home entertainment; family members and friends would gather to view slide shows. Reversal film was much in use, and supplied slides snapped during vacations and at family events. Slide projectors were also widely used in educational and other institutional settings. Photographic film slides and projectors have mostly been replaced by image files on digital storage media shown on a projection screen by using a video projector or simply displayed on a large-screen video monitor. History A continuous-slide lantern was patented in 1881. It included a dissolving views apparatus.Sloane, T. O'Conor. ''Facts Worth Knowing Selected Mainly from the Scientific American for Household, Workshop, and Farm Embracing Practical and Useful Information fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Contrast Sensitivity
Contrast is the contradiction in luminance or colour that makes an object (or its representation in an image or display) distinguishable. In visual perception of the real world, contrast is determined by the difference in the colour and brightness of the object and other objects within the same field of view. The human visual system is more sensitive to contrast than absolute luminance; we can perceive the world similarly regardless of the huge changes in illumination over the day or from place to place. The maximum ''contrast'' of an image is the contrast ratio or dynamic range. Images with a contrast ratio close to their medium's maximum possible contrast ratio experience a ''conservation of contrast'', wherein any increase in contrast in some parts of the image must necessarily result in a decrease in contrast elsewhere. Brightening an image will increase contrast in dark areas but decrease contrast in bright areas, while darkening the image will have the opposite effect. Ble ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Specular Reflection
Specular reflection, or regular reflection, is the mirror-like reflection of waves, such as light, from a surface. The law of reflection states that a reflected ray of light emerges from the reflecting surface at the same angle to the surface normal as the incident ray, but on the opposing side of the surface normal in the plane formed by the incident and reflected rays. This behavior was first described by Hero of Alexandria ( AD c. 10–70). Specular reflection may be contrasted with diffuse reflection, in which light is scattered away from the surface in a range of directions. Law of reflection When light encounters a boundary of a material, it is affected by the optical and electronic response functions of the material to electromagnetic waves. Optical processes, which comprise reflection and refraction, are expressed by the difference of the refractive index on both sides of the boundary, whereas reflectance and absorption are the real and imaginary parts of the re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mirror
A mirror or looking glass is an object that Reflection (physics), reflects an image. Light that bounces off a mirror will show an image of whatever is in front of it, when focused through the lens of the eye or a camera. Mirrors reverse the direction of the image in an equal yet opposite angle from which the light shines upon it. This allows the viewer to see themselves or objects behind them, or even objects that are at an angle from them but out of their field of view, such as around a corner. Natural mirrors have existed since prehistoric times, such as the surface of water, but people have been manufacturing mirrors out of a variety of materials for thousands of years, like stone, metals, and glass. In modern mirrors, metals like silver or aluminium are often used due to their high reflectivity, applied as a thin coating on glass because of its naturally smooth and very Hardness (materials science), hard surface. A mirror is a Wave (physics), wave reflector. Light consis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gloss (material Appearance)
Gloss is an optical property which indicates how well a surface reflects light in a specular (mirror-like) direction. It is one of the important parameters that are used to describe the visual appearance of an object. The factors that affect gloss are the refractive index of the material, the angle of incident light and the surface topography. Apparent gloss depends on the amount of ''specular'' reflection – light reflected from the surface in an equal amount and the symmetrical angle to the one of incoming light – in comparison with ''diffuse'' reflection – the amount of light scattered into other directions. Theory When light illuminates an object, it interacts with it in a number of ways: * Absorbed within it (largely responsible for colour) * Transmitted through it (dependent on the surface transparency and opacity) * Scattered from or within it (diffuse reflection, haze and transmission) * Specularly reflected from it (gloss) Variations in surface texture directly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barium Sulfate
Barium sulfate (or sulphate) is the inorganic compound with the chemical formula Ba SO4. It is a white crystalline solid that is odorless and insoluble in water. It occurs as the mineral barite, which is the main commercial source of barium and materials prepared from it. The white opaque appearance and its high density are exploited in its main applications.Holleman, A. F. and Wiberg, E. (2001) ''Inorganic Chemistry'', San Diego, CA : Academic Press, . Uses Drilling fluids About 80% of the world's barium sulfate production, mostly purified mineral, is consumed as a component of oil well drilling fluid. It increases the density of the fluid, increasing the hydrostatic pressure in the well and reducing the chance of a blowout. Radiocontrast agent Barium sulfate in suspension is often used medically as a radiocontrast agent for X-ray imaging and other diagnostic procedures. It is most often used in imaging of the GI tract during what is colloquially known as a "barium meal". ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Titanium Dioxide
Titanium dioxide, also known as titanium(IV) oxide or titania , is the inorganic compound with the chemical formula . When used as a pigment, it is called titanium white, Pigment White 6 (PW6), or CI 77891. It is a white solid that is insoluble to water, although mineral forms can appear black. As a pigment, it has a wide range of applications, including paint, sunscreen, and food coloring. When used as a food coloring, it has E number E171. World production in 2014 exceeded 9 million tonnes. It has been estimated that titanium dioxide is used in two-thirds of all pigments, and pigments based on the oxide have been valued at a price of $13.2 billion. Structure In all three of its main dioxides, titanium exhibits octahedral geometry, being bonded to six oxide anions. The oxides in turn are bonded to three Ti centers. The overall crystal structure of rutile is tetragonal in symmetry whereas anatase and brookite are orthorhombic. The oxygen substructures are all slight distort ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnesium Carbonate
Magnesium carbonate, (archaic name magnesia alba), is an inorganic salt that is a colourless or white solid. Several hydrated and basic forms of magnesium carbonate also exist as minerals. Forms The most common magnesium carbonate forms are the anhydrous salt called magnesite (), and the di, tri, and pentahydrates known as barringtonite (), nesquehonite (), and lansfordite (), respectively. Some basic forms such as artinite (), hydromagnesite (), and dypingite () also occur as minerals. All of those minerals are colouress or white. Magnesite consists of colourless or white trigonal crystals. The anhydrous salt is practically insoluble in water, acetone, and ammonia. All forms of magnesium carbonate react with acids. Magnesite crystallizes in the calcite structure wherein is surrounded by six oxygen atoms. The dihydrate has a triclinic structure, while the trihydrate has a monoclinic structure. References to "light" and "heavy" magnesium carbonates actually refer to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gain (projection Screens)
Gain is a property of a projection screen, and is one of the specifications quoted by projection screen manufacturers. Interpretation The number that is typically measured is called the peak gain at zero degrees viewing axis, and represents the gain value for a viewer seated along a line perpendicular to the screen's viewing surface. The gain value represents the ratio of brightness of the screen relative to a set standard (in this case, a sheet of magnesium carbonate Magnesium carbonate, (archaic name magnesia alba), is an inorganic salt that is a colourless or white solid. Several hydrated and basic forms of magnesium carbonate also exist as minerals. Forms The most common magnesium carbonate forms are ...). Screens with a higher brightness than this standard are rated with a gain higher than 1.0, while screens with lower brightness are rated from 0.0 to 1.0. Since a projection screen is designed to scatter the impinging light back to the viewers, the scattering can eit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inflatable Movie Screen
An inflatable movie screen is an inflatable framework with an attached projection screen. Inflatable screens are used for outdoor movies, film festivals, drive-in theaters, sports, social, fundraising and other events requiring outdoor projection. Design The projection frame is made from PVC-coated fabric layers joined by high-frequency welding or mechanical sewing. The projection surface can be made of PVC or spandex, with the latter providing for rear projection capabilities. The projection surface can be detachable for ease of care. The frame is inflated with a high-pressure air blower. Larger frames may require a three-phase blower. For bigger screens, the blower typically continues to operate, ensuring the screen remains fully inflated. For consumer market and smaller screen sizes, the screen is sealed and does not require a constantly operating air blower. Screens can be held upright with help of a supporting structure (A-frame or inflatable legs) or with the system o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Airscreen
An inflatable movie screen is an inflatable framework with an attached projection screen. Inflatable screens are used for outdoor movies, film festivals, drive-in theaters, sports, social, fundraising and other events requiring outdoor projection. Design The projection frame is made from PVC-coated fabric layers joined by high-frequency welding or mechanical sewing. The projection surface can be made of PVC or spandex, with the latter providing for rear projection capabilities. The projection surface can be detachable for ease of care. The frame is inflated with a high-pressure air blower. Larger frames may require a three-phase blower. For bigger screens, the blower typically continues to operate, ensuring the screen remains fully inflated. For consumer market and smaller screen sizes, the screen is sealed and does not require a constantly operating air blower. Screens can be held upright with help of a supporting structure (A-frame or inflatable legs) or with the system o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
