TV: TelevisionAll about TV, Satellite TV and future developments.

Television (TV) is a telecommunication medium for transmitting and receiving moving images that can be monochrome (black-and-white) or colored, with or without accompanying sound. "Television" may also refer specifically to a television set, television programming, or television transmission.

Commercially available since the late 1920s, the television set has become commonplace in homes, businesses and institutions, particularly as a vehicle for advertising, a source of entertainment, and news. Since the 1970s the availability of video cassettes, laserdiscs, DVDs and now Blu-ray Discs, have resulted in the television set frequently being used for viewing recorded as well as broadcast material. In recent years Internet television has seen the rise of television available via the Internet, e.g. iPlayer and Hulu.

Although other forms such as closed-circuit television (CCTV) are in use, the most common usage of the medium is for broadcast television, which was modeled on the existing radio broadcasting systems developed in the 1920s, and uses high-powered radio-frequency transmitters to broadcast the television signal to individual TV receivers.

The broadcast television system is typically disseminated via radio transmissions on designated channels in the 54–890 MHz frequency band. Signals are now often transmitted with stereo or surround sound in many countries. Until the 2000s broadcast TV programs were generally transmitted as an analog television signal, but in 2008 the USA went almost exclusively digital.

A standard television set comprises multiple internal electronic circuits, including those for receiving and decoding broadcast signals. A visual display device which lacks a tuner is properly called a video monitor, rather than a television. A television system may use different technical standards such as digital television (DTV) and high-definition television (HDTV). Television systems are also used for surveillance, industrial process control, and guiding of weapons, in places where direct observation is difficult or dangerous.
Amateur television (ham TV or ATV) is also used for non-commercial experimentation, pleasure and public service events by amateur radio operators. Ham TV stations were on the air in many cities before commercial TV stations came on the air.

Some TV channels are partly funded from subscriptions therefore the signals are encrypted during broadcast to ensure that only the paying subscribers have access to the decryption codes to watch pay television or specialty channels. Most subscription services are also funded by advertising.

Worldwide large-screen television technology brand revenue share in Q3 2011
Manufacturer Display Search.
SAMSUNG 22.8%
LG 13.1%
Sony 9.9%
Panasonic 8.4%
Sharp Corporation 7.6%
Others 38.2%

Worldwide TV Shipments by Technology in Q3 2011
Technology Display Search
LCD TV 83.1%
PDP TV 6.7%
OLED TV 0.0%
CRT TV 10.2%
RPTV 0.0%
Total 100%

Aspect ratio incompatibility: 16:9 & 4:3

The television industry's changing of aspect ratios is not without difficulties, and can present a considerable problem. Displaying a widescreen aspect (rectangular) image on a conventional aspect (square or 4:3) display can be shown: in "letterbox" format, with black horizontal bars at the top and bottom
with part of the image being cropped, usually the extreme left and right of the image being cut off (or in "pan and scan", parts selected by an operator or a viewer) with the image horizontally compressed A conventional aspect (square or 4:3) image on a widescreen aspect (rectangular with longer horizon) display can be shown: in "pillar box" format, with black vertical bars to the left and right
with upper and lower portions of the image cut off (or in "tilt and scan", parts selected by an operator) with the image vertically compressed

A common compromise is to shoot or create material at an aspect ratio of 14:9, and to lose some image at each side for 4:3 presentation, and some image at top and bottom for 16:9 presentation. In recent years, the cinematographic process known as Super 35 (championed by James Cameron) has been used to film a number of major movies such as Titanic, Legally Blonde, Austin Powers, and Crouching Tiger, Hidden Dragon (see also: Films shot in Super 35). This process results in a camera-negative which can then be used to create both wide-screen theatrical prints, and standard "full screen" releases for television/VHS/DVD which avoid the need for either "letterboxing" or the severe loss of information caused by conventional "pan-and-scan" cropping.