High definition television sets are a familiar sight in countless living rooms up and down the country these days. Yet whilst more and more consumers are enjoying the fantastic viewing experience afforded by HD TV, many of us still don’t know exactly what it’s all about and what the jargon actually means. It helps to know the technical terms, simply so that you can take better advantage of the deals and offers available on HD TV packages from manufacturers such as Sky.
First off, you need to know that there are different high-definition formats available on the market. More recent HD flat screens offer a resolution of 1366 x 768 pixels, typically using display formats of 720p and 1080i. Larger signals can be downscaled to fit, of course, but to display 1080i and 1080p signals in full, you would need to have a screen with a resolution of 1820 x 1080 pixels – or Full HD, as it’s understandably known.
What do these bewildering numbers all actually mean though? These numbers (720p, 1080i or 1080p) are formats in which sources of content are presented, before they are transmitted through the output device which for most people will be the LCD or plasma screen. In the simplest of terms, the higher the format, the larger screen resolution required to display it in its entirely – bearing in mind that a lower resolution screen will still be able to display it, albeit a downscaled version.
The resolution of a television screen is ultimately the number of pixels it can display, and this depends on the display unit and the video signal being received. Resolution has a horizontal and a vertical figure of course, given that video images are always rectangular in shape.
720p and 1080i were the original standards for HD television, and the first high definition devices supported these formats. The old-fashioned television set with its CRT display used a stream of electrons which is sent across the face of a tube coated in phosphors which then glow to finally give you the picture. This explains the diagonal lines you might sometimes have seen on an old television screen if it is not properly tuned.
However new technology brought progressive scanning, with which frames connect more easily, giving better quality and improved picture detail – similar, in fact, to how films are shown at the cinema.
High definition television is the point at which we’ve arrived in the development of this technology. Most high definition television is broadcast in either 720p or 1080i, so if you have a screen which can’t display 1080p then it probably won’t be a problem unless you’re an avid game player keen with a console that requires graphics displayed this way.
But for all that, the difference between these formats remains all but insignificant. So you have to make the decision what kind of screen you want depending on your needs, bearing in mind that with any format you will get incredible picture quality and ambience.