What is high-definition television?

High-definition television, or HDTV, is a new standard of television broadcasting that provides a sharper picture. It uses approximately four times the number of pixels as conventional television, allowing near-cinematic picture quality, and incorporates richer stereo sound.

Why would I want it?

The picture quality is very sharp, sharp enough that some American television presenters are unhappy with its tendency to reveal the spots, flaws and plastic surgery scars that standard television concealed. "The difference in resolution is staggering," according to Chris Ayres, The Times's Los Angeles Correspondent, who has been enjoying American HD broadcasts for years.

Will I need new equipment?

Yes. You will need an HD-ready television set and an HDTV decoder, which is similar to a Sky or Freeview set-top box. If you want to get the best sound quality you will also need a Dolby Digital 5.1 surround sound system.

How much will it cost?

It’s not cheap, although as ever with electronics the price is likely to fall. HD-ready televisions are already getting cheaper and it is possible to find 32-inch sets for about £600. If you want the full HD experience you will need a larger screen, anything bigger than 36 inches is likely to cost more than £1,000. Respected brands such as Sony Bravia are closer to £3,500 for 40-inch models.

The Sky HD decoder box costs £299 and the HD service costs £10 per month on top of any other Sky services you choose. The BBC does not charge for its HD service, but you will need either the Sky HD box or a cable HDTV service in order to receive the signal.

Can I get HDTV through my Freeview box?

No. There isn’t room on the spectrum for high-definition signals, which contain much more data than the conventional signal. The BBC says that it may be able to deliver HDTV using Freeview once the analogue signal has been switched off, freeing up more of the spectrum for digital broadcasts.

If I buy an HD-ready television, will I see all programmes in high-definition?

No, only programmes that are broadcast in high-definition format will benefit from being seen on the new screens. Although an increasing number of shows will adopt the HD format, to begin with the vast majority of shows will be broadcast in the standard 576-line resolution. If you buy a much larger television the standard television picture may even look worse because each pixel is bigger.

What will I be able to watch?

The BBC is putting on HD coverage of the World Cup and Wimbledon and will also broadcast about two hours per day of dramas and documentaries from BBC One and BBC Two. Sky will show Premiership Football and other sporting events, as well as films, documentaries and dramas. If you have a high-definition DVD player you will also be able to watch HD DVDs as they become available.

Is there more than one HDTV format?

Of course there is. The two formats currently available are called 720p, which displays 720 lines of pixels using progressive scanning, and 1080i, which displays 1080 lines of pixels using interlaced scanning. Progressive scanning updates all the pixels in a single sweep, while interlaced scanning updates half the pixels in one sweep and the other half in another. Both standards give a similar picture quality and you will be able to watch all HDTV broadcasts regardless of which format you use.

What’s the difference between HDTV, HD-DVD and BluRay?

HDTV refers to broadcast television, whereas HD-DVD and BluRay are rival formats of high-definition DVD. To watch the new DVDs you will need an HD-ready television and a new DVD player, but not a set-top box.

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