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Vision Electronic Recording Apparatus
Vision Electronic Recording Apparatus (VERA) was an early analog recording videotape format developed from 1952 by the BBC under project manager Dr Peter Axon. History In order to record high frequencies, a tape must move rapidly with respect to the recording or playback head. The frequencies used by video signals are so high that the tape/head speed is on the order of several meters per second (tens of feet per second), an order of magnitude faster than professional analog audio tape recording. The BBC solved the problem by using reels of magnetic tape that passed static heads at a speed of . VERA was capable of recording about 15 minutes (e.g. 4,572 meters) of 405-line black-and-white video per reel, and the picture tended to wobble because of some jitter (uneven speed) of the tape transport. Later video recorders used a time base corrector to remove this jitter and make synchronization with the studio house possible. In order to cope with 625-line PAL or SECAM colour t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnetic Tape
Magnetic tape is a medium for magnetic storage made of a thin, magnetizable coating on a long, narrow strip of plastic film. It was developed in Germany in 1928, based on the earlier magnetic wire recording from Denmark. Devices that use magnetic tape can with relative ease record and play back audio, visual, and binary computer data. Magnetic tape revolutionized sound recording and reproduction and broadcasting. It allowed radio, which had always been broadcast live, to be recorded for later or repeated airing. Since the early 1950s, magnetic tape has been used with computers to store large quantities of data and is still used for backup purposes. Magnetic tape begins to degrade after 10–20 years and therefore is not an ideal medium for long-term archival storage. The exception is data tape formats like Linear Tape-Open, LTO which are specifically designed for long-term archiving. Information in magnetic tapes is often recorded in tracks which are narrow and long areas of in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Panorama (British TV Programme)
''Panorama'' is a British current affairs documentary programme broadcast on the BBC. First broadcast in 1953, it is the world's longest-running television news magazine programme. ''Panorama'' has been presented by many well-known BBC presenters, including Richard Dimbleby, Robin Day, David Dimbleby and Jeremy Vine. , it broadcasts in peak time on BBC One, without a regular presenter. The programme also airs worldwide through the international feed of the BBC News channel in many countries, and domestically via the UK feed. History ''Panorama'' was launched on 11 November 1953 by the BBC; it emphasises investigative journalism. '' Daily Mail'' reporter Pat Murphy was the original presenter, who only lasted one episode after accidentally broadcasting a technical mishap. Max Robertson then took over for a year. The programme originally had a magazine format and included art features. In September 1955, when Richard Dimbleby took over as presenter, it got the subtitle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Audiovisual Introductions In 1952
Audiovisual (AV) is electronic media possessing both a sound and a visual component, such as slide-tape presentations, films, television programs, corporate conferencing, church services, and live theater productions. Audiovisual service providers frequently offer web streaming, video conferencing, and live broadcast services. The professional audio visual industry has companies that provide hardware, software and services. These organizations are commonly referred to as ''systems integrators'' and perform both the installation and integration of different types of AV equipment from multiple manufacturers into spaces to create the AV experience for the user or audience. Computer-based audiovisual equipment is often used in education, with many schools and universities installing projection equipment and using interactive whiteboard technology. Components Aside from equipment installation, two significant elements of audiovisual are wiring and system control. If either of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Science And Media Museum
The National Science and Media Museum (formerly The National Museum of Photography, Film & Television, 1983–2006 and then the National Media Museum, 2006–2017), located in Bradford, West Yorkshire, is part of the national Science Museum Group in the UK. The museum has seven floors of galleries with permanent exhibitions focusing on photography, television, animation, videogaming, the Internet and the scientific principles behind light and colour. It also hosts temporary exhibitions and maintains a collection of 3.5 million pieces in its research facility. The venue has three movie theatre, cinemas, including Europe's first opened IMAX screen, finished in April 1983. It hosts festivals dedicated to widescreen film, video games and science. It has hosted popular film festivals, including the Bradford International Film Festival, until 2014. In September 2011 the museum was voted the best indoor attraction in Yorkshire by the public, and it is one of the most visited mu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helical Scan
Helical scan is a method of recording high-frequency signals on magnetic tape, used in open-reel video tape recorders, video cassette recorders, digital audio tape recorders, and some computer tape drives. With this technique, magnetic tape heads (or head chips) are placed on a rotating head drum, which moves the chips at high speed by due to its high angular velocity. The speed of the head chips must be higher than the linear speed of the tape. The tape is wrapped tightly around the drum. The drum and/or the tape is tilted at an angle that allows the head chips to read the tape diagonally. The linear speed of the tape is slower than the speed of the head chips, allowing high frequency signals to be read or recorded, such as video. As the tape moves linearly or length-wise, the head chips move across the width of the tape in a diagonal path. Due to geometry, this allows for high head chip speeds, known as writing speeds, to be achieved in spite of the low linear speed of the tap ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digital Audio Tape
Digital Audio Tape (DAT or R-DAT) is a signal recording and playback medium developed by Sony and introduced in 1987. In appearance it is similar to a Compact Cassette, using 3.81 mm / 0.15" (commonly referred to as 4 mm) magnetic tape enclosed in a protective shell, but is roughly half the size at 73 mm × 54 mm × 10.5 mm. The recording is digital rather than analog. DAT can record at sampling rates equal to, as well as higher and lower than a CD (44.1, 48, or 32 kHz sampling rate respectively) at 16 bits quantization. If a comparable digital source is copied without returning to the analogue domain, then the DAT will produce an exact clone, unlike other digital media such as Digital Compact Cassette or non- Hi-MD MiniDisc, both of which use a lossy data-reduction system. Like most formats of videocassette, a DAT cassette may only be recorded and played in one direction, unlike an analog compact audio cassette, although many DAT recorders had ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quadruplex Videotape
2-inch quadruplex videotape (also called 2" quad video tape or quadraplex) was the first practical and commercially successful analog recording video tape format. The format uses magnetic tape and was developed and released for the broadcast television industry in 1956 by Ampex, an American company based in Redwood City, California. The first videotape recorder using this format was built the same year. This format revolutionized broadcast television operations and television production, since the only recording medium available to the TV industry until then was motion picture film. Since most United States network broadcast delays by the television networks at the time used kinescope film that took time to develop, the networks wanted a more practical, cost-effective, and quicker way to time shifting, time-shift television programming for later airing in Western time zones than the expensive and time-consuming processing and editing of film. Faced with these challenges, broadc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ampex
Ampex Data Systems Corporation is an American electronics company founded in 1944 by Alexander M. Poniatoff as a spin-off of Dalmo-Victor. The name ''AMPEX'' is an acronym, created by its founder, which stands for Alexander M. Poniatoff Excellence.AbramsoThe History of television, 1942 to 2000– McFarland, 2003 – , page 286, Chapter 2, footnote 34 "1944 he founded Ampex (the name was created from his initials, AMP, plus "ex" for excellence)" Ampex operates as Ampex Data Systems Corporation, a subsidiary of Delta Information Systems, and consists of two business units. The Silicon Valley unit, known internally as Ampex Data Systems (ADS), manufactures digital data storage systems capable of functioning in harsh environments. The Colorado Springs, Colorado, unit, referred to as Ampex Intelligent Systems (AIS), serves as a laboratory and hub for the company's line of industrial control systems, cyber security products and services and its artificial intelligence/machine learnin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SECAM
SECAM, also written SÉCAM (, ''Séquentiel de couleur à mémoire'', French for ''sequential colour memory''), is an analog color television system that was used in France, Russia and some other countries or territories of Europe and Africa. It was one of three major analog color television standards, the others being PAL and NTSC. Like PAL, a SECAM picture is also made up of 625 interlaced lines and is displayed at a rate of 25 frames per second (except SECAM-M). However, due to the way SECAM processes color information, it is not compatible with the PAL video format standard. SECAM video is composite video; the luminance (luma, monochrome image) and chrominance (chroma, color applied to the monochrome image) are transmitted together as one signal. All the countries using SECAM have either converted to DVB, Digital Video Broadcasting (DVB), the new pan-European standard for digital television, or are currently in the Digital television transition, process of conversion. S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
System A
CCIR System A was the 405-line analog broadcast television system adopted in the UK and Ireland. System A service started in 1936 and was discontinued in 1982 in Ireland and 1985 in Britain. Specifications Some of the important specs are listed below. * Frame rate: 25 Hz * Interlace: 2/1 * Field rate: 50 Hz * Lines per frame: 405 * Line rate: 10.125 kHz * Visual bandwidth: 3 MHz * Vision modulation: AC3 positive * Preemphasis: none * Sound modulation: A3 * Sound offset: -3.5 MHz * Channel bandwidth: 5 MHz A frame is the total picture. The frame rate is the number of pictures displayed in one second. But each frame is actually scanned twice interleaving odd and even lines. Each scan is known as a field (odd and even fields.) So field rate is twice the frame rate. In each frame there are 405 lines (or 202.5 lines in a field.) So the line rate (line frequency) is 405 times the frame frequency or 405×25=10,125 Hz. The video bandwidth w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Black-and-white
Black-and-white (B&W or B/W) images combine black and white to produce a range of achromatic brightnesses of grey. It is also known as greyscale in technical settings. Media The history of various visual media began with black and white, and as technology improved, altered to color. However, there are exceptions to this rule, including black-and-white fine art photography, as well as many film motion pictures and art film(s). Early photographs in the late 19th and early to mid 20th centuries were often developed in black and white, as an alternative to sepia due to limitations in film available at the time. Black and white was also prevalent in early television broadcasts, which were displayed by changing the intensity of monochrome phosphurs on the inside of the screen, before the introduction of colour from the 1950s onwards. Black and white continues to be used in certain sections of the modern arts field, either stylistically or to invoke the perception of a hist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
405-line Television System
The 405-line monochrome analogue television broadcasting system was the first fully electronic television system to be used in regular broadcasting. The number of television lines influences the image resolution, or quality of the picture. It was introduced with the BBC Television Service in 1936, suspended for the duration of World War II, and remained in operation in the UK until 1985. It was also used between 1961 and 1982 in Ireland, as well as from 1957 to 1973 for the Rediffusion Television cable service in Hong Kong. 405-line was approved as System A in the CCIR assignment of broadcast systems. Sometimes called the Marconi-EMI system, it was developed in 1934 by the EMI Research Team led by Isaac Shoenberg. The figure of 405 lines had been chosen following discussions over Sunday lunch at the home of Alan Blumlein. The system used interlacing; EMI had been experimenting with a 243-line all-electronic interlaced system since 1933. In the 405 system the scanning l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
