The fuzzy logic of digital TV technology

Buying a new TV has never been so problematic, and the industry is as confused as shoppers – a worrying start for the post-analogue era

Have you tried to buy a new television set recently? My faithful cathode-ray set still has a great picture after ten years, but it’s not widescreen and it takes up a huge amount of room, front to back. It was time for a change – but it took me almost a year to buy a replacement, and not just because I was waiting for prices to come down after the World Cup.

Like buying a coffee, choosing a TV is much more complicated than it used to be. The manufacturers and retailers make it even more complex than it should be.

Analogue or digital? 4 x 3 or 16 x 9? Cathode ray, LCD, plasma or back-projection? High definition “compatible” or high definition “ready”? Scart sockets, HDMI interfaces or AV/S-video? That’s before you decide how big a screen you want and whether it should be wall-mounted, table-top or free-standing. Not to mention home cinema and surround-sound.

I knew I wanted a wide screen and a flat panel. I thought I wanted either 26″ or 32″ – which simplified matters because it ruled out the plasma option – and I obviously wanted the sharpest possible picture.

Have you seen the picture quality in most TV shops? It is remarkably bad, considering they are trying to encourage people to buy TV sets. For a while I thought it was my eye-sight. One problem is that most retailers don’t ensure there’s a high-quality feed going into the sets, which means the pictures are fuzzy and it’s impossible to judge which set is the best.

What’s worrying is that this is sometimes as good as it gets. One of the best-kept secrets in television is that many flat panel TVs aren’t as good as the old cathode ray tube ones. Mike Briggs, a television expert at the consumer group Which?, recently told The Independent: “Chances are, normal TV programmes won’t look as good on a flat-panel set as on a conventional box.”

Which? says picture quality has actually declined in recent years. The bigger the set is, the worse the picture becomes, because it magnifies all the faults – which is why many people believe that high definition TV (HD) has a great future. Without it, some experts say, large sets are simply too fuzzy to watch.

In the shops, HD sets look terrific – and much better quality than the rest. But HD introduces another can of worms. To start with, it’s not enough just to buy an HD set. To get HD pictures, you need to pay for an HD receiver box, either from Sky or Telewest, plus a subscription to watch the HD channels. In the case of SkyHD, the box costs 300 and the extra subscription is 10 a month.

And it’s not even clear what an HD set is. Some are labelled “HD compatible” and some are “HD ready”. What’s the difference? One retailer on its website says: “HD warning. Beware of our competitors advertising HD compatible LCDs and plasmas. These are of a lower spec than HD ready LCDs and plasmas, and are unlikely to work with high definition broadcasts. All of our HD ready LCDs and plasmas are clearly marked and, rest assured, are fully compatible with the new high definition broadcasts.”

A Web “jargon buster” defines “HDTV compatible” as: “HDTV which does not support the required HDCP to warrant an “HD ready” logo. However, these will generally still accept high definition pictures of an HD-component input.”

Don’t you love jargon busters that spout more jargon? This one then explains that HDCP stands for “high definition copy protection”: “This is the de facto standard for preventing digital copies of high definition video. In order for a TV to carry an ‘HD ready’ logo, it must have a digital input that is capable of handling the HDCP encrypted signal.”

Don’t ask how it defines HD-component… But the confusion is about to get worse, for there is a new version of HD called “full HD”.

Last week Sharp Electronics took over the Imagination Gallery to demonstrate its full HD sets. Its press release claims: “A new standard in high definition has just arrived… Compared to the widely-used 1,366 x 768 picture resolution found on standard HD ready TVs, Sharp’s Aquos full HD models provide a resolution of 1,920 x 1,080. In simple terms, this means twice the number of pixels (6.2 million versus 3.1 million).”

Even if you can decide which set and which system to buy, there’s the question of how much HD programming you’ll actually be able to watch.

Sky and the BBC have done a very good pioneering job. The BBC’s Bleak House and Planet Earth and Sky’s Premiership football coverage really do set a new standard in picture quality. Sky broadcasts several channels in HD, including Sky Sports, Sky Movies, Sky One, Artsworld, Sky Box Office, National Geographic and Discovery, as well as a BBC channel.

Many commercials are now shot in HD and they look and sound terrific.

But what about the rest of the output – ITV, Channel 4, Five and the hundreds of digital channels now available? If, as Which? says, normal TV programmes don’t look as good on a flat-panel set as they do on a conventional box, the digital future is distinctly fuzzy.