Broadcasting Systems

Broadcasting is the transmission of a program or information by radio 

or television. One way to broadcast is by cable. This is where the 

program is transmitted over the cable directly to the receiver TV. 

Cable was created in 1947 by John Walson and was originally called 

CATV (Community Antenna Television). Two advantages to cable 

are, it has a better reception and has a better picture and sound. A 

disadvantage is that cable isn't available in as many places as satellite.

Satellite is another way to broadcast programs. Satellite is a signal that is sent to satellites orbiting the earth and then amplifies the signal before sending it  back down to earth. The first satellite television broadcast was in 1978 and was developed to direct to home receivers in 1980. Two advantages to satellite are, it is available in areas that cannot receive cable. And it provides a sharper image than off air broadcast. A disadvantage is that the weather can disrupt connection.

Freeview is a free digital broadcasting system. It receives digital terrestrial transmission and can be used with any TV. Freeview was launched in 2002, it was jointly operated by five shareholders, BBC, ITV, Channel 4, BSkyB and Arqiva. Two advantages of Freeview are, its free and safe. And provides a weeks listing of programs. A 

disadvantage is that it not available everywhere in the UK.

Internet TV is a digital download of programs via the internet. Internet TV became very popular in the UK through BBC iPlayer, 4oD, ITV Player and Demand Five. Two advantages to internet TV are, its available everywhere that there is an internet connection. It has old shows available that aren't on TV anymore. A disadvantage is, they often include adverts.

White Balance and Colour Temperature

Colour temperature is the way to describe the colours that the lighting of the set gives off. Colour temperature is measured in Kelvin (K), colder colours have a higher K, and warmer colours have a lower K. A blue sky on a clear day is 9500K which is near the top of the scale, the preset balance to use for this would be Daylight Balance. Opposite to this is candle light at 1500k at the bottom of the scale. The lighting for this would be very orange.



White Balance is what the camera values as white and it can be changed manually. The white balance is used best when it is set to the same K as the colour temperature that the lighting gives off.











To balance a DSLR camera, hold a white sheet of paper, with the light from the set on it, in front of the cameras and press the WB button. The camera also offers some preset white balanced settings but they might not be good enough.





White balancing a camera is important because it prevents unrealistic casts of light and produces an image that better resembles what the human eye can see.