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Hydrargyrum Medium-arc Iodide Lamp
Hydrargyrum medium-arc iodide (HMI) is the trademark name of Osram's brand of metal-halide gas discharge medium arc-length lamp, made specifically for film and entertainment applications. ''Hydrargyrum'' comes from the Greek name for the element mercury. An HMI lamp uses mercury vapour mixed with metal halides in a quartz-glass envelope, with two tungsten electrodes of medium arc separation. Unlike traditional lighting units using incandescent light bulbs, HMIs need electrical ballasts, which are separated from the head via a header cable, to limit current and supply the proper voltage. The lamp operates by creating an electrical arc between two electrodes within the bulb that excites the pressurized mercury vapour and metal halides, and provides very high light output with greater efficiency than incandescent lighting units. The efficiency advantage is near fourfold, with approximately 85–108 lumens per watt of electricity. Unlike regular incandescent halogen lamps where ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Color Rendering Index
A color rendering index (CRI) is a quantitative measure of the ability of a light source to reveal the colors of various objects faithfully in comparison with a natural or standard light source. ''Color rendering'', as defined by the International Commission on Illumination (CIE), is the effect of an illuminant on the color appearance of objects by conscious or subconscious comparison with their color appearance under a reference or standard illuminant. The CRI of a light source does not indicate the apparent color of the light source; that information is given by the correlated color temperature (CCT). The CRI is determined by the light source's spectrum. An incandescent lamp has a continuous spectrum, a fluorescent lamp has a discrete line spectrum; implying that the incandescent lamp has the higher CRI. The value often quoted as "CRI" on commercially available lighting products is properly called the CIE Ra value, "CRI" being a general term and CIE Ra being the interna ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Broadcast Television Systems
Broadcast television systems (or terrestrial television systems outside the US and Canada) are the encoding or formatting systems for the transmission and reception of terrestrial television signals. Analog television systems were standardized by the International Telecommunication Union (ITU) in 1961, with each system designated by a letter ( A- N) in combination with the color standard used (NTSC, PAL or SECAM) - for example PAL-B, NTSC-M, etc.). These analog systems for TV broadcasting dominated until the 2000s. With the introduction of digital terrestrial television (DTT), they were replaced by four main systems in use around the world: ATSC, DVB, ISDB and DTMB. Analog television systems Every analog television system bar one began as a black-and-white system. Each country, faced with local political, technical, and economic issues, adopted a color television standard which was grafted onto an existing monochrome system such as CCIR System M, using gaps in the v ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Beat Frequency
In acoustics, a beat is an interference pattern between two sounds of slightly different frequencies, ''perceived'' as a periodic variation in volume whose rate is the difference of the two frequencies. With tuning instruments that can produce sustained tones, beats can be readily recognized. Tuning two tones to a unison will present a peculiar effect: when the two tones are close in pitch but not identical, the difference in frequency generates the beating. The volume varies as in a tremolo as the sounds alternately interfere constructively and destructively. As the two tones gradually approach unison, the beating slows down and may become so slow as to be imperceptible. As the two tones get further apart, their beat frequency starts to approach the range of human pitch perception, the beating starts to sound like a note, and a combination tone is produced. Mathematics and physics of beat tones This phenomenon is best known in acoustics or music, though it can be found in any ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
HMI Ballast Front
HMI may refer to: Companies and organizations * Hahn-Meitner-Institut, now Helmholtz-Zentrum Berlin, a German research institute * Hanson Musical Instruments, a manufacturer of electric guitars * Hartz Mountain Industries, an American holding company * HD Mining International, a mining company in Vancouver, British Columbia, Canada * Hetrick-Martin Institute, an LGBT youth organization in New York City * High Mountain Institute, in Leadville, Colorado, United States * Himalayan Mountaineering Institute, in Darjeeling, India * HMI Hotel Group, a hotel management company in Japan * Holistic Management International, an American non-profit organization * HornAfrik Media Inc, a media organization based in Mogadishu, Somalia * Hotel Meliá, in Ponce, Puerto Rico * Houston Mechatronics, Inc, see Houston Mechatronics, Inc * Hualien Media International, a global entertainment company in Taipei, Taiwan * Muslim Students' Association (Indonesia) Technology * Helioseismic and Magnetic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Emission Spectrum
The emission spectrum of a chemical element or chemical compound is the Spectrum (physical sciences), spectrum of frequencies of electromagnetic radiation emitted due to electrons making a atomic electron transition, transition from a high energy state to a lower energy state. The photon energy of the emitted photons is equal to the energy difference between the two states. There are many possible electron transitions for each atom, and each transition has a specific energy difference. This collection of different transitions, leading to different radiated wavelengths, make up an emission spectrum. Each element's emission spectrum is unique. Therefore, spectroscopy can be used to identify elements in matter of unknown composition. Similarly, the emission spectra of molecules can be used in chemical analysis of substances. Emission In physics, emission is the process by which a higher energy quantum mechanical state of a particle becomes converted to a lower one through the emis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Blackbody
A black body or blackbody is an idealized physical body that absorbs all incident electromagnetic radiation, regardless of frequency or angle of incidence. The radiation emitted by a black body in thermal equilibrium with its environment is called ''black-body radiation''. The name "black body" is given because it absorbs all colors of light. In contrast, a white body is one with a "rough surface that reflects all incident rays completely and uniformly in all directions." A black body in thermal equilibrium (that is, at a constant temperature) emits electromagnetic black-body radiation. The radiation is emitted according to Planck's law, meaning that it has a spectrum that is determined by the temperature alone (see figure at right), not by the body's shape or composition. An ideal black body in thermal equilibrium has two main properties: #It is an ideal emitter: at every frequency, it emits as much or more thermal radiative energy as any other body at the same temperature. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Fluorescent Lights
A fluorescent lamp, or fluorescent tube, is a low-pressure mercury-vapor gas-discharge lamp that uses fluorescence to produce visible light. An electric current in the gas excites mercury vapor, to produce ultraviolet and make a phosphor coating in the lamp glow. Fluorescent lamps convert electrical energy into visible light much more efficiently than Incandescent light bulb, incandescent lamps, but are less efficient than most LED lamps. The typical luminous efficacy of fluorescent lamps is 50–100 lumens per watt, several times the efficacy of incandescent bulbs with comparable light output (e.g. the luminous efficacy of an incandescent lamp may only be 16 lm/W). Fluorescent lamp fixtures are more costly than incandescent lamps because, among other things, they require a electrical ballast, ballast to regulate Electric current, current through the lamp, but the initial cost is offset by a much lower running cost. Compact fluorescent lamps (CFL) made in the same sizes a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Vari-Lite
Vari-Lite is a brand of automated, variable-colour stage lighting systems. Their intelligent lighting fixtures are commonly used in theatre, concerts, television, film and Corporate entertainment, corporate events. History Pre-history The origins of Vari-Lite date to the late 1960s, when college friends Jack Calmes and Rusty Brutsché played together in a Texas-based blues band. They built a Sound reinforcement system, sound system for their shows that attracted the attention of other acts, who asked to Renting, rent it from them. In March 1970, Calmes and Brutsché, together with sound engineer Jack Maxson, incorporated Showco, with the intention of supplying sound systems to regional rock concerts. The company initially operated two sound systems and two trucks from Maxson's garage. The company quickly grew, both in size and reputation, and added lighting equipment to its inventory in 1972. By the end of the 1970s, Showco's lighting equipment was becoming outdated, and the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Philips
Koninklijke Philips N.V. (), simply branded Philips, is a Dutch multinational health technology company that was founded in Eindhoven in 1891. Since 1997, its world headquarters have been situated in Amsterdam, though the Benelux headquarters is still in Eindhoven. The company gained its royal honorary title in 1998. Philips was founded by Gerard Philips and his father Frederik, with their first products being light bulbs. Through the 20th century, it grew into one of the world's largest electronics conglomerates, with global market dominance in products ranging from kitchen appliances and electric shavers to light bulbs, televisions, cassettes, and compact discs (both of which were invented by Philips). At one point, it played a dominant role in the entertainment industry (through PolyGram). However, intense competition from primarily East Asian competitors throughout the 1990s and 2000s led to a period of downsizing, including the divestment of its lighting and c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Film Industry
The film industry or motion picture industry comprises the technological and commercial institutions of filmmaking, i.e., film production company, production companies, film studios, cinematography, animation, film production, screenwriting, pre-production, post production, post-production, film festivals, Distribution (marketing), distribution, and actors. Though the expense involved in making film almost immediately led film production to concentrate under the auspices of standing production companies, advances in affordable filmmaking equipment, as well as an expansion of opportunities to acquire investment capital from outside the film industry itself, have allowed independent film production to evolve. In 2019, the global box office was worth . When including box office and Home video, home entertainment revenue, the global film industry was worth in 2018. Cinema of the United States, Hollywood is the world's oldest national film industry, and largest in terms of box-office ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
