What is HD? - Active Home

High-definition (HD) TV is taking the nation by storm. Now that shop windows are emblazoned with the latest and greatest deals on HD-ready TVs, you might well ask yourself whats it’s all about and why do I need one?

Put simply, HD offers up to four times more detail than DVD or digital TV broadcasts, meaning sharper pictures and a richer viewing experience. Watching a wildlife documentary in HD gets you closer to the animals than ever before, and football matches come alive with incredibly defined pitches, stadiums and crowds.

What do I need?
To view HD broadcasts your first port of call will be a television or projector capable of displaying high-definition pictures. This means one with a sufficient screen resolution and the right connectors.

In order to display high-definition video properly, a television or projector needs to have a resolution of at least 720 physical lines in wide-aspect ratio. It must have component and DVI or HDMI inputs and support HDCP. The HD inputs should accept signals at 1,280x720 (720p) and 1,920x1,080 (1080i).

If that sounds like gobbledegook, relax; all TVs and projectors that meet these requirements can claim to be officially ‘HD-Ready’ and will display the official HD-Ready logo on the box to confirm that fact.

The Sony BRAVIA W-Series comes in a choice of 40in or 46in screen sizes, features uncompromising 1080p resolution and high-performance LCD panel technology for exceptionally wide viewing angles. A specially designed Wide Colour Gamut backlight, precision matched filters in the screen and real-time signal processing by the BRAVIA Engine combine to boost the range of colour the W-Series can display.

This Live Colour Creation system, together with the HD 1808 panel, gives the W-Series its very distinctive and special advantage over conventional LCD TVs. To round things off, both models are equipped with an integrated digital TV tuner for Freeview and twin HDMI inputs for connection to HD set-top boxes, HD recorders and PlayStation 3.

Sound quality also has a big role to play in the HD revolution. Not only have pictures improved, but more and more content is also being produced and broadcast with 5.1-audio soundtracks that, with the right equipment, can transform a living room into a living theatre. All you need is a surround-sound amplifier and a connecting set of 5.1 speakers.

The Sony HT-SF1000 covers all the bases. It sports a powerful 1,000W amplifier, a design-conscious set of 5.1 floor-standing speakers and an HDMI connection for a crisp HD picture. It also decodes Dolby Digital and DTS soundtracks, which is the audio that is usually attached to films and HD broadcasts.

How do I get HD?
HD-Ready televisions may be in abundance but the source of content is still fledgling. Presently, only Sky, NTL Telewest and the BBC are broadcasting HD content over the airwaves, so you’ll need to be signed up with one of these to get HD in the home. We’ll delve into what type of content each broadcaster is offering later.

Any programme that claims to be HD has to be produced using HD cameras and then broadcast in HD. A brand new HD-ready television or HD projector won't transform a standard-definition programme into an HD one either, so you'll need a set-top box such as those supplied by Sky or NTL Telewest.

Another way to get HD into the home is through a computer. Sony’s latest VAIO XL200-Series PCs are more like home-entertainment devices, capable of playing back HD content in the form of Blu-ray discs and downloadable HD video from the nternet.

In keeping with the industry’s focus on digital connections, the VAIO XL200-Series has an HDMI port for hooking up to a television or amplifier to maintain that smart high-definition picture and sound. The XL200-Series is designed specifically to sit under your LCD TV.

Sony’s new camcorders can now shoot in HD, and we’ll be focusing on those later.
Blu-ray is a big talking point of the year and very soon HD movies will be appearing on this very format. Capable of storing up to 50GB of data, these high-capacity discs will be great for backing up large numbers of computer documents and archiving large volumes of music, video and photos.

In 2007 we’ll see yet another way of getting HD content into the home with the arrival of the Sony PlayStation 3, which has a Blu-ray player for playing HD movies and games.

Digital details
The difference between standard-definition TV broadcasts and HD content lies with the amount of detail that is shown in an image. This figure is measured by ‘resolution’ and all HD displays should be able to handle a 1,920x1,080 resolution (1,920 pixels wide and 1,080 pixels high). Compare this with a standard-definition television that can only support around 852x480 pixels and the difference in resolution becomes apparent.

HD content is broadcast in three resolution types; 720p, 1080i and 1080p. 1080i is an ‘interlaced’ format, which means more lines and pixels but 720p is a ‘progressive-scan’ format, which takes a purer form that should make video content look smoother and sharper. Although in its infancy, the 1080p resolution combines best of both worlds, presenting the clearest, cleanest picture that today’s HD displays can handle.

Most programme information will display what resolution it’s being broadcast in, but at present only a small number of displays can currently handle the 1080p format. As HD grows in stature and popularity over the new few years, expect prices of 1080p displays to fall and more programming to be broadcast at this HD resolution.

See also: