Tech Buzz: What is a TV Aspect Ratio?

What is a TV Aspect Ratio?

When referring to televisions, the aspect ratio essentially tells us the shape of a TV image - and is also used to refer to the shape of our televisions.

The ratio that it refers to is the width of the image divided by the height.

4:3 TV Aspect Ratio

For those of you old enough to remember (ok, we're not actually going that far back!), the traditional shape of a television screen was almost square. It was slightly wider than it was high, but not by much.

This TV screen shape was designed to match the shape of the images that were sent to our TVs, and it was known as a "4 by 3" image - also known as 4:3 or 4x3.

This means that the image was 4 units wide and 3 units high. The physical size of the units doesn't matter - it could be 4 inches by 3 inches, 4 feet by 3 feet or 8 feet by 6 feet - but the relationship between the width and the height is always 4 across and 3 down.

As the actual size of the image doesn't matter, it is often easier to express this 4:3 relationship as a ratio. This means that if we divide the width by the height, then 4 ÷ 3 = 1.33.

So 1.33 (or 1.33:1) is said to be the aspect ratio of a 4:3 TV image or television.

You will often find the aspect ratio referred to as either of these two numbers, but they both mean the same thing. When you do see these terms, then it is just telling you the basic shape of an image or screen.

What is a 16:9 Widescreen TV Aspect Ratio?

As with all technology, times change and the boffins try and improve on what we already have. Therefore, it was thought that this traditional 4:3 aspect ratio used in television viewing could be improved.

16:9 Widescreen TV Aspect Ratio

Although originally 1.33:1, the traditional aspect ratio of movies has for a long time been different to the 'square' images were used to seeing on our televisions. This meant the image shape was much wider than it was high. You can see this by the wide shape of the screen in a cinema or movie theater.

This wide image shape was thought to more closely reflect the way that our eyes worked - and so was a more natural way for us to see things.

With the introduction of HDTV and digital television, the result has been a slow but steady switch to 'widescreen' televisions.

The widescreen image we see on our TVs isn't quite the same shape as they use in movies, but it is similar.

The actual shape that has become standard for HDTVs is a "16 by 9" image. This is the standard HD aspect ratio. As with a 4:3 image, this means that the picture is 16 units wide and 9 units high - therefore much wider in comparison to the height.

You're probably way ahead of me now, but we can also express this widescreen image as a ratio.

Therefore, 16 ÷ 9 = 1.77. This number is usually rounded up to 1.78 - so when you see a reference to 1.78 or 1.78:1, then you know that the image or TV screen will be widescreen - or 16:9.

Read more: http://www.the-home-cinema-guide.com/tv-aspect-ratio.html#ixzz2Fne8lnYm