High Definition television pictures are made up of over two million coloured dots. These dots change approximately 25 times per second.

On the left, is a simulated HD example . It is a much sharper image with more coloured dots making up the picture. On the right is a simulated SD or standard definition picture made up of less dots, hence there is much less detail in the picture.

HDTV is free to view digital tv lets you enjoy crystal clear pictures accompanied by high quality sound, which is now capable of Dolby 5.1 or 7.1 surround sound in the comport of your home. It’s a powerful viewing experience that provided a new level of enjoyment only available on free to view digital tv. Free to view digital tv pictures can be delivered in either Standard Definition (SD) or High Definition (HD) format.

HD broadcasts offer crystal clear pictures with up to three times the horizontal and up to twice the vertical resolution of SD on some programming. This creates an amazingly detailed, lifelike image that approaches film quality, with clear, sharp edges, realistic colours and greater depth of vision. You’ll need an HD screen to show the improved picture quality, with the benefits most noticeable on larger screens – whether CRT, rear projection, plasma, LCD or home theatre projector. A HD screen will be in a widescreen shape, the maximum resolution HDTV in Australia is 1080i and all broadcasters are currently using this format. 1080i refers to how many horizontal lines makeup the picture. "1920" in 1920 x 1080 refers to the number of dots or pixels that make up each horizontal line. 1920 x 1080 is currently the highest picture quality available.

How do I receive free to view High Definition tv?

To receive and watch free to view High Definition tv you either need a television screen with built-in HD digital tv reception capabilities or an HD set top box connected to an HD screen. All HD integrated televisions and HD set-top boxes can receive both HD and SD broadcasts, and Dolby Digital audio with HD broadcast.

Can I connect a High Definition set top box to an older analogue or SD TV?

Yes. The majority of High Defintion digital set top boxes on the market can receive the HD and SD TV channels and output a normal standard defintion picture to an older TV. If you wish to use the red, green and blue (component) video connections, which is capable of both HD and SD resolutions or (composite), which is only standard defintion, you may need to read the manual to find out how to set set top box to the correct screen resolution to match your older TV. 576i will be the setting required.

HD broadcasts provide high quality sound without the distortions found in analog TV.

HD programs can be broadcast with Dolby Digital 2/0 stereo or MPEG audio. Some broadcasters enhance programs with multi-channel audio, including Dolby Pro Logic or Dolby Surround. Some broadcasters also provide Dolby Digital 5.1 sound dependent upon availability of the soundtrack.

Connecting leads between an HD set top box and screen

Currently, HD set top boxes are commonly connected to an HD screen by either a digital HDMI cable or analogue such as Component (YpbPr) or RGB. The resolution and picture quality may be affected by the cable type and length. Special HDMI cables can transmit a HD signal up to 20m without substantial signal loss, however these cables can be expensive. For the fore mentioned reasons it's best to keep you cable lengths to a minimum, i.e. under 10 metres. A high quality cable will be able to handle the wider digital or analogue bandwidth required for HD (typically up to 30MHz), cheaper cables do not have sufficient screening for interference and the picture quality will suffer as a result. The introduction of digital video connectors (DVI and HDMI) provide improved picture quality over analog connectors – similar to the difference between analog audio and digital audio connectors.

Why can't I hear the HD channels in Surround Sound?

You'll need to check that your amplifier is set up correctly and you have a coaxial or optical audio cable connected to your amp from your HD TV / set top box. However, not all TV programmes are transmitted, or produced for that matter, in surround sound. The HD channels are capable of transmitting surround sound formats up to Dolby 7.1, however most programmes are produced in stereo. In 2010 Fox Sports Australia will be producing all of their sporting programmes in Dolby 5.1 and many other free to air channels are starting to jump on board with the new surround formats. The Friday night AFL matches on Channel 10 are produced and transmitted in Dolby 5.1, Channel 9's Cricket series and a handful of big budget variety programmes are also taking the leap, but it's a costly and difficult process to produce a TV programme in Dolby 5.1, so it may be a while before it becomes the norm.

What's the difference between HD ready, HDTV, HD and True HD?

Buyer beware! HD written on a TV or set top box does not mean it's 1920 x 1080 or "True HD". It seems that some manufactures tend to confuse or mislead potential buyers with terms like HD ready, HD and True HD. HD Ready is not full high defintion! It's was more common a few years ago to see these TVs advertised left right and centre, but now HD Ready seems to only exist in smaller TVs (less than 40inch) and the larger less expensive models. The resolution of these screens is only 1366 x 768 or less, and they're sort of half way between the quality of SD and HD. Unfortunately, there is a lot of video processing going on to fit the TV picture into this space. The confusing part is that these TVs can receive HD TV channels, but they downgrade them to SD so you can see them on the screen. So effectively you can watch what's on the HD channels, but you certainly don't get the clarity that goes along with High Definition broadcasts.