The difference between standard definition and Hi definition is the resolution and sharpness of the pictures.

Standard definition television uses 625 lines and Hi Definition delivers 1080 lines which means that there is a considerable improvement in the resolution and detail in the picture. Hi Definition video contains around four times the picture information compared to standard definition (SD).

In retail outlets we see the "HD Ready" sticker on TV screens, what exactly does HD ready mean?

First of all, HD ready televisions are actually HDTV 'monitors' as they don't have HD receivers built into them. To view high definition images, you will need a decoder or set-top box, i.e. SKY HD or a BluRay player; its just a next generation DVD player.

Please be aware that HD ready stickers doesn't necessarily mean that the TV will display full high definition images.

Put simply, most HD ready TVs will down-convert the incoming HD signal to a lower resolution that the TV can display. This down conversion produces considerably less quality than the original full HD image.

To view the best possible high definition images, look out for the 1080p sticker on the HDTV. These TVs are getting more common.

True 1080p content is extremely scarce and as none of the major networks currently broadcast 1080p images the only way to experience full HDTV 1080p at the moment is by viewing BluRay disks.

Having said that, Sky 1080i HD broadcasts can be stunning.

Sky viewers should be aware that a considerable amount of programmes shown on the Sky HD channels are actually non-HD programmes being shown on an HD channel.
If you press the 'info' button on your sky handset you should see 'HD' on the right hand side of your info bar. If you don't see 'HD' then your watching standard definition on an HD channell.

Many new DVD players upscale standard definition films in order to fit on the screen.
All upscale does is stretch the smaller pixels into bigger softer ones.
It never makes the picture sharper or adds detail that wasn’t there.
Upscaling from non-HD images does not deliver HDTV.

Click for full HD 1920 x 1080 image (1:133)

© PETER BURNS 2006