Anamorphic DVD's & Aspect Ratios

4:3, 16:9, Anamorphic, Widescreen, CinemaScope, Panavison, Pan & Scan, Letterbox - the list goes on! But what do all these alien names mean? When we go to the cinema to watch a movie we will see a picture like the one below:

But when we watch the same movie on VHS video we may get something like this:

It is a terrible loss of detail, I know. In the past TV screens could not show wide pictures. So the film industry thought up ways they could convert widescreen movies so they can be viewed on our home TV's.

LETTERBOXING

In the picture below the red outline represents the size of your TV. With Letterboxing the picture is shrunk to fit the whole thing in and black bars are added at the top and bottom to fill the gaps.

PAN & SCAN

This method is called Panning and Scanning because the the movie is re-recorded from the cinema screen, but the camera pans left and right to scan only for the parts of the movie that are vital. Most old VHS movies are Pan & Scan and, as a result, many of the fine details of the movie were lost. In the picture below the red square represents the only parts of the movie that would be recorded to video with Pan & Scan.

ANAMORPHIC RESIZING

Anamorphic resizing is the royal magic trick of the DVD revolution. The whole movie is recorded at full resolution but the image is literally squashed out of shape and no fine details are lost! It is only with the relatively new introduction of wide screen TV's that it has been possible to view anamorphic movies at full resolution. A DVD player has a built in function that allows it to re-stretch an Anamorphic movie out to full size again. This way anamorphic DVD are able to take full advantage of whatever extra resolution specifications advances in TV technologies make. If your TV is not wide enough to take an anamorphic image, then the image will just be Letterboxed and look like any widescreen movie.

If you have already decoded a Widescreen DVD to your computer, you will probably find that the picture is still squashed. It is not an error with the ripping process, but rather the computers inability to resize the image as would be done on a normal DVD player. The above picture is a 720 x 576 PAL rip, but when opened in a DVD player it will be resized to something like 852 x 480!

If you find that the DVD of your favorite movie doesn't say widescreen, it may be an idea to wait a bit before you buy it. Sometimes they are replaced by the widescreen versions later on, and you will end up buying the movie twice, no doubt to the joy of the movie industry =).

Aspect Ratios

Yes, many of you have looked on a DVD box and read Anamorphic Widescreen 16:9 2.35:1 and thought 'what the Fu*k!' Nevertheless, most of you will be familiar with the idea of ratios even if you think you don't. Imagine, for example, you are mixing a cocktail drink. It is four parts vodka to three parts of soda. That would be a ratio of 4:3. It doesn't matter if you used four gallons of vodka to every three gallons of soda, or four egg cups of vodka to every three egg cups of soda, it would still be a ratio of 4:3!

Aspect ratios work exactly the same way. Interestingly enough, your TV screen is probably an aspect ratio of 4:3 too =o). That is, three parts down by four parts across. But to say a picture is always four by three parts makes it hard to make exact measurements. Instead an alternative system is used; we measure the height and the width. For example, in the image below we have a ratio of 1.33:1 (or 1.33 to 1). The 1 can be anything. Imagine, for example, the blue rectangle below was 1 meter high. The width would then be 1.33 meters across, or, if you like: 1 meter and 1 meter 33 centimeters wide.

This is why aspect ratios are used on DVD's. It doesn't matter what measurements we use, it could be millimeters, centimeters, pixels, points, whatever. It always remains in perfect shape if we resize it by the aspect ratio it was originally. There are a couple of 4:3 aspect ratios, for example 1.25:1, 1.36:1, but DVD's that say a ratio of 4:3 will usually use 1.25:1.

A second very often used aspect ratio is 16:9. That is, sixteen parts to every nine parts. This is basically what you will get from a widescreen TV.

There are a myriad of possible ratios for widescreen. But probably the most used of them for DVD's will be 1:85:1 (American), 1.66:1 (European), 1.77:1 (British) and especially CinemaScope at 2.35:1 (worldwide). CinemaScope are also sometimes called Panavision or just WideScreen. Of course, it could be a mistake to say any aspect ratio is just British or just American etc., because studios just use the ratios they feel are best for their audience.