Hi-Def (HD) in a nutshell…
You can’t go into a TV shop nowadays without being bombarded with Hi-Def televisions. How did we ever survive without them!
I believe though, that many people don’t know what Hi-Def really means, so let me explain.
Hi Def basically means that the picture you are seeing has a greater resolution and is in widescreen format.
What does greater resolution mean? Well in Standard definition (what we had all along), the resolution was 720*568. You can picture that your television screen is made up of rows and columns of dots, each with a different colour. So, standard definition had 720 columns of dots and 568 lines. Hi Definition has a few different flavours but I will talk about the one that will become the norm. It has a resolution of 1440*1080. This means 1440 columns and 1080 rows. This means that you have twice the number of rows and columns of dots than standard definition which means a much clearer picture with more detai.
What does widescreen mean? In the past most televisions were not widescreen, they had an aspect ratio of 4*3. This means that for every 4 dots across, there were 3 dots down. This means that the TV was nearly square. Widescreen television have an aspect ration of 16*9 which means that for ever 16 dots across, there are 9 dots down. It is a much more rectangular shape.
If you are watching a widescreen movie on an old style TV, you would see black bars on the top and bottom of the screen. This is because you are viewing a rectangular image on a square TV. If you have a widescreen TV this doesn’t happen, as the movie and TV have the same shape.
Older video cameras used to record in non-widescreen mode. They were designed for producing video to be played back on older televisions. You could switch many of these cameras into a widescreen mode but there was a sacrifice in quality.
Hi Def video cameras are designed to record in widescreen mode so you are getting more detail and a video that is designed to be played on your widescreen TV.
For a more detailed explanation, just go to…
