What is widescreen TV?

A substantial amount of digital TV programming (mainly that being broadcast by the BBC), is broadcast in the 16:9 or ‘widescreen’ format. This means that the transmitted picture has an aspect ratio of 16:9 – i.e. the ratio between the screen’s horizontal dimension and its vertical one is 16 to 9.

However, an ordinary TV set has a screen where the ratio of the screen’s horizontal dimension to its vertical dimension is 4:3 (i.e. it’s nearly square). This can’t properly display widescreen pictures, which are more ‘rectangular’: either some of the picture needs to be chopped off to fit, or it needs to be reduced in size (which gives a so-called ‘letterbox’ effect, in that there is a wide black horizontal band above and below the picture). This effect is particularly noticeable with films, since the majority of them have been shot with more ‘rectangular’ screen ratios.

Given the amount of digital TV programming being broadcast in widescreen mode, almost all IDTVs sold have 16:9 screen displays. This, together with the enhanced picture and sound quality, contributes towards the ‘home cinema’ effect – which is seen as one of digital TV’s major selling-points. You can also benefit from the ‘home cinema’ effect by attaching a digital decoder to an analogue widescreen TV set, and, early in 2006, by signing up for BSkyB's HDTV service.