HDTV is one of the recent advancements in television technology. Since 2005, more and more plasma TVs have become packaged with HDTV, so what exactly is it? To begin with, HDTV stands for 'High Definition' TV, and simply put, it denotes the ability of a TV to display a high resolution. Plasma screens which can display a HD signal are said to be HD ready, or HD compatible.

HDTV broadcasts are delivered in a 16:9 wide-screen format, this is the same aspect ratio in which movies are made. Most plasma TVs are manufactured to be native in a 16:9 aspect ratio. NTSC signals are transmitted with an aspect ratio of 4:3, this has meant that most TVs have cut 20% of the image signal sent. When you read the subtitles of a movie or documentary, you will have noticed that the writing moves off the screen's edge.

Generally speaking, a HDTV must meet a minimum resolution standard of 1024 x 720, which is provided via a HDMI/DVI input (they are then classified as HD-Ready). A HD ready TV must have HDMI or DVI connectivity in order to accept a digital signal from HD receiving equipment. Alongside this, an analogue component (YpbPr) connection is usually provided.

At the moment the technologies which are HD Ready,

• CRT
• CRT projection
• PDP (plasma)
• LCD
• LCD projection
• LCoS projection
• DLP projection

Screen resolutions:
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The promise of HDTV is to produce a well defined picture, as explained before, a plasma image is composed of millions of small dots; which are named pixels. Whereas a typical TV image is composed of around about 366,600 pixels, a 720p HDTV image has around 920,600 pixels.

While resolution is a good indicator of a quality screen image, it's not the only process in the melting pot. Computer control systems like Panasonic's VIERA help to alter the colour, brightness and contrast levels of a screen image. Therefore, it's important not to solely relay on the screen resolution alone when choosing a new plasma television.

The native resolution is the standard resolution of the plasma television, and it is not the resolution of the delivery signal. If the native resolution of a screen is 1024X1024, and delivery signal is 1024X768, the TV will convert the delivery signal to the native resolution of the TV. The closer these signals are in resolutions, the better the image will be. That is why a HD Ready television will display a high definition signal better than a traditional television.

The native resolution of a HD Ready television does not alter; therefore, it's ideal to find a native resolution that's as close to the true HDTV signal of 1080p as possible. Finally, if you're wondering what the difference between plasma and LCD is, check the site's plasma vs lcd article.

A/V connections:
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Most standard definition TV's come with composite, SD component, S-Video, and SCART connections. SCART being the most popular for Europe and the UK. HDTV sets requires a HDMI/DVI connection.