High-Definition Television FAQ
High-definition Television (HDTV) is being touted as the next big thing in home entertainment, but what is it? should you get it? and is it really worth it? Read on!
- What is high-definition television?
- How is high-definition different from digital television?
- How does high-definition compare to standard definition television systems?
- What high-definition resolutions are available?
- What equipment do I need to watch HDTV
- What type of television do I need?
- Can I use my existing decoder/set-top box?
- Where I can get high-definition content to watch?
HDTV is a new broadcasting format offering improved picture and audio quality.
The kind of picture quality improvment you can expect from HDTV
Most simply, a high-definition television system is able to offer a clearer and more detailed picture than any existing broadcast system, because it contains more picture information. All television signals, whether analogue or digital, are made up of many dots or picture elements (pixels) that form the image you see, so by using more of these pixels in a high-definition (HD) transmission a better image can be produced.
Digital television (DTV) is a transmission method that will continue to be used to broadcast high-definition signals. In the same way that audio quality was improved moving from analogue music cassettes to Compact Discs, a similar change is happening to television.
The first stage of this has been to 'digitise' the existing analogue television system, that is to take the same picture information but broadcast it digitally rather that using analogue. The amount of picture information does not change, but digital transmission is more efficient than analogue resulting in a more consistent picture quality and an improved range of available channels.
In time the next stage of this process will be to use this improved digital technology to deliver improved picture and sound quality; high-definition.
Read more about digital television
An HD signal can contain up to around five times the picture information compared to standard definition (SD). Standard definition pictures are made up of approximately 500-600 horizontal lines of pixels depending on the local transmission system used, whereas high-definition transmissions use at least 700 to around 1000 lines as illustrated below.
Common Picture Resolutions
High definition broadcasts also include better native support for multi-channel sound and windscreen formats which can improve the experience of sport and movies.
Two different picture resolutions are commonly used for high-definition television, they are named after the number of horizontal picture lines they use, either HD720 or HD1080 containing 720 and 1080 lines respectively.
Read more about high-definition formats
It is quite unlikely that you will currently have all the necessary equipment to receive high-definition television; the most basic system must have all of the following:
- You will need an 'HD Ready' television set or equivalent that has an increased picture resolution
- A decoder or set-top box to receive high-definition broadcasts
- A TV service offering HD programming
In order to simplify the process of buying a new television, most high-definition capable displays feature the 'HD Ready' logo which indicates that a display will be compatible with other HD devices and is able to display the improved image resolution high-definition offers. This means it must have:
- At least 720 lines of horizontal picture resolution in a widescreen aspect ratio and be able to display 720 and 1080 line content
- The necessary connection to interface with HD set-top boxes and next generation games consoles and DVD players. This is called an HDMI input which must also support the HDCP copy protection system.
Read more about HD Ready
Existing standard definition digital set-top boxes will not be compatible with high-definition services. Currently and for the foreseeable future the majority of new HD televisions will not contain a high-definition receiver, so to watch HD television programmes a new HD set-top box will be necessary.
High-definition television channels/programming, if not already available from your service provider (normally as an upgrade or separate product) soon will be, and will likely be delivered via the same physical means; cable, satellite, over-the-air etc.
Next-generation games consoles including Microsoft's X-Box 360 and Sony's Playstation 3 support high-definition gaming, and similarly the new DVD formats, HD-DVD and Blu-Ray are designed to natively carry HD content.
Before making an early investment in high-definition products and services it is worth taking the time to ensure that the HD content you actually want to watch is available and available to you.