High Definition Explained
High Definition TV crops up quite a lot in our podcasts. This page contains explains the basics of Hi-def.
We took a run-through of Hi-Def TV in Show 23 of our podcast. |
What is High Definition TV?
HD (Hi-definition) offers a higher quality picture with more vibrant colours, greater detail, crisp clarity and amazing sound quality.
High Definition TV uses with loads more pixels than standard TV.
HD launched in the UK in May 2006. To get it, you'll need a TV with the "HD Ready" logo, plus a set-top box that delivers HD pictures.
At the time of writing, Sky & Virgin Media are offering HD TV in the UK.
What do I need to get HD TV?
You'll need a TV set that's capable of getting HD TV - Look for the "HD Ready" logo. For an HD TV, try Currys or Misco
You also need to get an HD TV service. Here are the key UK HD TV content providers:
| Sky HD |
At the time of writing, there are over 60 HD channels available, including: BBC One HD, BBC Two HD, Sky 1 HD, ITV 1 HD, ITV 2 HD, Channel 4 HD, Channel 5 HD, National Geographic HD, Sky Atlantic HD, Discovery HD, Biography HD, Bio HD, SyFy HD, History HD, 4 Sky Sports HD channels, ESPN HD, History HD, Crime HD, Disney Cine HD, Eurosport HD, nine Sky HD movies channels, Sky Arts HD, plus pay-per-view Box Office movies in HD.
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| Virgin Media |
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| BT Vision |
BT Vision set-top boxes are HD-ready. No live TV is available in HD with BT Vision, however a small collection of movies and TV shows in HD are now available for download on BT Vision. |
| Freesat | Freesat is a joint venture between the BBC and ITV. No subscription is required, and the service offers over 170 standard definition TV and radio channels. Freesat offers 5 HD channels: BBC One HD, BBC Two HD, ITV1 HD, Channel 4 HD and NHK World HD (Japan) with an HD Freesat box and a satellite dish. More information on Freesat on our Freesat information page |
| HD on Freeview | Freeview HD launched on the 2nd of December 2009 , and now offers BBC One HD, BBC Two HD, ITV1 HD and Channel 4 HD to parts of the UK. For more, see our HD on Freeview page, or sign up for updates. |
Sky is currently leading the field, offering a High Definition set-top box and subscription, and the strongest lineup of HD programming currently on offer in the UK.
Virgin Media currently offers over 28 HD channels including BBC One HD, BBC Two HD, ITV1 HD, Channel 4 HD, Sky One, Living HD, E4 HD, Fox HD, SyFy HD, Discovery HD, National Geographic HD, MTVN HD and Eurosport HD. For an additional subscription fee, there's Sky Sports 1, Sky Sports 2 and ESPN HD. There's also on-demand HD content including Movies on Demand, TV choice, and More On Demand.
Screenshot of Sky Digital EPG showing HD content
Your HD questions answered
Q. Is it possible to output HDMI to my HD TV, and output sound to my analogue amp at the same time? Is there any difference between HDMI and component? (TJ Ford, Aug 2008).
Yes, and Yes. On the second question - An HDMI socket and a set of Component sockets are capable of transmitting High Definition. HDMI is digital, and also carries the audio signal. Component is analogue and doesn't carry audio. Many argue that, quality-wise over short distances, there's little between the two. For more on this, check out the detailed article at ecoustics.com. If you need cables, try TV Cables or Maplin
Q. Can you explain the different HD formats?
There are four HD formats in use in the UK - 720i, 720p, 1080i and 1080p:
- 720 or 1080? - 720 or 1080 represents the number of horizontal lines that make up the picture. Standard definition TV is made up of 576 horizontal lines. 1080 lines will show more detail than 720 lines.
- 'i' or 'p' - The 'i' represents 'interlaced', and the 'p' is for 'progressive' scan. This describes the process used to display an image on screen. 'Progressive' shows the entire frame in one go, whereas an Interlaced picture draws only half of the image in one go - all of the odd-numbered lines, then all of the even number of lines. The TV blends the two interlaced fields together. 'p' is the better of the two, especially for faced moving images. On larger screens, you may notice flicker with interlaced.
Which is best? That'd be 1080p, which offers the maximum amount of detail and the best quality. 1080p is often referred to as "Full HD". Broadcast TV only offers 720p or 1080i, and so you're only going to get the best from a 1080p TV by connecting to a BluRay player or 1080p capable games console.
Q. What is the difference between HD-Ready and "Full HD"? We read out this question, asked by Brian White, in show 37.
The numbers 720 and 1080 are used when talking about HD, to represent the number of lines used on-screen. Then there's a "p" or an "i", for the "progressive" or "interlaced" format. Technically, "1080p" is at the top end of the four HD variants, and it's this format that's what's called "Full HD". You should be aware that, at the moment, the likes of Sky are only using 720p and 1080i for their HD service. There are many people that believe the average viewer won't see much of a difference between 1080i and 1080p, other than to their wallets!
We're keen to expand the information we have about High Definition TV on this page. What would you like to know? What are your views on HDTV in the UK?
Got any questions we can help with? Please let us know.
Other Links:
- TV & Tech HD Help - Your HD questions answered
We took a run-through of Hi-Def TV in Show 23 of our podcast. |
Got a question on HD TV that we can answer in our next podcast?
Call 020 8133 4567 or send us a message
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