High Definition Satellite (Sky) TV Costa Blanca Spain

High-Definition TV (HDTV) is the most exciting thing to happen to television since black and white turned to colour. And with a HD satellite receiver you can receive crystal clear satellite TV channels, and in many cases with Dolby Digital sound.

The main fact you need to know is that HDTV pictures contain four times as much picture definition as the standard TV pictures we watch currently. This translates into a picture that is crystal clear and bursting with extra clarity, sharpness, depth and a realism that is impossible to believe without seeing it for yourself. Sound quality is also typically far better with HDTV as most High-Definition programmes contain 5.1 Dolby Digital surround sound.

A TV picture is made up of tiny dots called pixels. A standard definition (SD) TV programme is made up of pixels. SD TVs were all designed with a similar number of pixels to show the programmes in the best quality. So, because TV programmes have – until recently – been available in standard definition, your large screen, HD Ready TV picture has actually been ‘stretched’ to fit the screen – losing some of the quality.

Now many programmes are broadcast in HD which means they’ll fit perfectly on your new TV giving you deeper, richer, more vivid colours. And many programmes are available with stunning surround sound. Overall, HD gives you an unforgettable TV experience.

Is it as complicated as it sounds?

High-Definition TV is not as complicated as you might think, but there are two basic obstacles to your High-Definition viewing pleasure. Firstly, you can only receive HD images from a HD-capable source box, such as SkyHD or Freesat. Secondly, you can only view true HD images on special HD Ready screens. This effectively means that the home entertainment systems the vast majority of us currently have simply will not cut the mustard come the High-Definition revolution.

The difference between Standard Definition (SD) and High Definition (HD) is simulated below.

What is the difference between analogue, digital, and HDTV?

Analogue TV: An analogue television is capable only of displaying standard definition images as currently found on terrestrial, cable, Freeview and satellite broadcasts. Analogue televisions cannot display High-Definition pictures.

Digital TV: A digital television operates using digital rather than analogue signals and broadcasts in true widescreen format. Digital televisions can display HD pictures, though not to their true resolution.

HDTV: A High-Definition television can display analogue, digital and true High-Definition TV signals, although there are a variety of important factors to consider when picking the best television for your needs. The main areas to look at are:

Connections – HD signals can only commonly be transported by HDMI/DVI inputs, component inputs or 15-pin PC connections; so your screen will need one or more of these to receive HD pictures. HDMI stands for High Definition Multimedia Interface. This is a bit of a mouthful. Basically it is a standardised format for the cables and sockets that connect the different pieces of an HDTV system together. It is a replacement for the commonplace SCART connection that is currently in use, as SCART is not capable of handling the high quality HD picture format.

Formats – The two key HD formats are 1080i and 720p. Neither is necessarily better that the other, but your TV needs to be able to handle both for true High-Definition pictures from all sources. For a more in-depth look at this, scroll down to ‘Resolutions’.

Getting regular TV and DVD on an HDTV

High-Definition televisions can play regular TV broadcasts as well as HDTV, and will usually make the images better, as most HDTVs feature progressive-scan (an image improvement) technology. This is not always the case however, as the larger the TV you own (and HDTVs are generally 26 inches or larger), the bigger the flaws in its images become. This is particularly the case with fast-moving programming, like football. One of the main reasons for buying an HDTV, even if you do not have an HDTV tuner or receiver, is DVD. The combination of progressive-scan technology in an HDTV set and progressive-scan compatible DVD player ensures the very best image possible is produced. Watching a DVD in this way means you are getting the best possible picture available, outside of HDTV itself

HDTV Resolutions

All digital displays make their pictures up using pixels, where the more pixels a screen has, the better the image. This is called the screen resolution and it is well worth having a basic knowledge of the resolution formats if you want to make the most informed choice when purchasing your new HD kit.

The two formats for High-Definition are 720p and 1080i. The 1080i format contains 1080 lines of image information, which is produced using the interlaced (hence the i) system. This means the pictures on your television are produced in two separate sweeps, with the odd lines (1, 3, 5, 7 etc) created during the first sweep and the even lines (2, 4, 6, 8 etc) created during the second. The sweeps are so quick, however, that the human eye sees only one complete image.

The 720p format, while having fewer lines of image information, uses progressive-scan technology (hence the p), where all the lines are created at once, as opposed to two separate sweeps. This ensures an exceptionally smooth image, which is often preferable to 1080i for fast-moving footage (again, such as football).

To give you an idea of what these numbers mean, the standard definition pictures you currently enjoy use only 576-625 lines of information in the interlaced format.

Does Size Matter? 16:9 vs 4:3

Television screens are available in two shapes, regular (4:3 aspect ratio) and widescreen (16:9). Regular pictures are four inches wide to three inches high, while widescreen pictures are 16 inches wide to nine high. Traditionally, films are shot in widescreen format, while TV is shot in regular – hence the black bars that run across the top and bottom of a screen when you watch a film on a regular television.

But as technology improves and with the launch of High-Definition (which is shot in widescreen format), the only real choice is to opt for a widescreen TV when making your next purchase. Almost all large (28-inch and above) screens are now only available in widescreen format though, making it an easy decision to make!