High definition TV explainedHD TV services

If you buy an HD-ready television, don’t expect to get home, plug it in and start watching TV the likes of which you’ve never seen before. HD pictures are more detailed so take up a lot of space.

You also need to sign up to an HD subscription service. At the moment only digital satellite and cable have the necessary capacity to broadcast HDTV programmes.

Sky and Virgin (formerly NTL/Telewest) both offer this on top of their normal digital TV service. Programmes have to be specially made in HD, and then broadcast in HD too. So an HD-ready TV or an HD service won't turn a standard-definition programme into an HD one.

Sky HD (satellite)

What is it?

The Sky HD service is an add-on to the digital TV service. If you’re a new customer you’ll need to sign up to one of Sky’s digital TV packages as well as the HD service.

If you’re an existing customer you can upgrade to the HD service. New customers pay £299 for the Sky HD set-top box and £60 for installation.

The HD service itself costs £10 per month on top of your chosen Sky TV subscription. But you have to make sure the channel you want to watch is included in your Sky TV package. For example, to watch Sky Sports HD you must subscribe to the Sky’s Sports Mix.

For information about mixes see our guide to digital TV options or www.sky.com.

The Sky HD box with remote allows you to record programmes too

The Sky HD box is one of our Best Buy PVRs. It has a built in recorder that allows you to record digital and HD programmes.

It has all the functionality of the excellent Sky plus box but with the added bonus of HD. You'll be able to watch both HD and standard definition channels.

What can I watch in Sky HD?

Sky has 11 designated HD channels: Sky Sports HD 1 & 2; Sky Box Office HD; Sky Movies HD 9 & 10: Sky One HD; Artsworld HD; National Geographic HD; Discovery HD; The History Channel HD; and BBC HD. But they don’t all show HD programmes all the time.

Sky Movies HD broadcasts entirely in HD, but most of the channels only show select programmes in HD with the rest in standard definition.

The Sky TV Guide tells you which programmes are in HD. Sky is planning to add more HD channels and programmes in the near future. You can visit Sky’s website to find out more about this service.

Virgin Media(cable)

What is it?

NTL:Telewest is now called Virgin Media

To watch HD programmes on cable you need to sign up to the V+ service, offered by Virgin Media (formerly known as ntl:Telewest). To get this you must subscribe to one of their digital TV packages.

The V+ box is a PVR that also decodes HD broadcasts. We don’t rate the V+ box as highly as the Sky box, but it is cheaper to get hold of.

Sky charges £359 for the HD box and installation but these are both free with Virgin Media. You do, however, have to pay a monthly fee for the V+ box.

The Telewest HD box now renamed the V+

This is an extra £10 or £15 per month on top of your digital TV subscription (depending on which package you’re on). See Virgin Media for more details of cost and packages.

What can I watch in HD?

Virgin Media doesn’t offer as many programmes in HD as Sky. Its HD service gives you access to BBC HD and additional HD content on demand.

You can't get Sky Sports in HD on cable (but you can get it in non-HD format).

Freeview HD

What is it?

In 2006 the BBC, ITV, C4 and C5 trialled the transmission of HD content on digital terrestrial TV – via rooftop aerials – in parts of London. Events such as the World Cup and Wimbledon, along with a variety of dramas, documentaries and films were all broadcast in HD.

The trials proved it’s technically possible to transmit HD programmes down your aerial, and in September 2007 the BBC announced plans for a cut-down HD service on Freeview. HD takes up a lot of room and the spare bandwidth freed up by analogue switch off is likely to go to the highest bidder, so the BBC plans to broadcast 4 hours a day overnight.

You'll need a new set-top box to decode the signals, so the BBC may delay the launch of the service so audiences don't have to buy yet another new piece of kit, so close to digital switchover.

Freesat

As well as terrestrial Freeview, the most likely place we'll see a free-to-air HD service is via Freesat – a new satellite service to be launched by the BBC and ITV in 2008. Freesat will not require any subscription fee, just a 1-off payment for a box and dish. If you want to watch the HD offerings, a Freesat HD PVR will be available.

Similarly, if HDTV does end up being broadcast on terrestrial Freeview, it's highly unlikely that your current set-top box of IDTV will be able to pick up the signal. IDTVs will need another decoder (or set-top box) to receive terrestrial HD signals.

Terrestrial digital will in that respect be no different to cable or satellite digital, which also require another decoder box.

However, digital TVs and Freeview set-top boxes will not suddenly become obsolete. If terrestrial HDTV is launched, standard definition content will still be broadcast in the same way.

What can I watch in HD?

In the meantime, BBC and ITV are still making some HD programmes, such as Planet Earth, Torchwood and Robin Hood, but they can only be broadcast in HD on satellite and cable. If you don’t have an HD-ready television you can still watch these programmes but you won’t get the full HD experience.

Nevertheless, because of the way they’re recorded, pictures are still noticeably better quality when shown on a standard TV set. So, in 1 way or another, we can all reap the benefits of HDTV.