Video aspect ratios
Everything you need to know about common video aspect ratios such as 2.35:1, Widescreen, FullScreen, Pan and Scan, Letterbox, etc.
The image aspect ratio is its displayed width divided by its height (usually expressed as 'x:y').
For instance, the aspect ratio of a traditional television screen is 4:3, or 1.33:1. High definition television uses an aspect of 16:9, or about 1.78:1. Aspect ratios of 2.39:1 or 1.85:1 are normally used for movies, while the aspect ratio of a full 35 mm film frame with soundtrack (known as 'Academy standard') is around 1.37:1.
The 4:3 ratio for standard television has been in use since television's origins and many computer monitors use the same aspect ratio. Since 4:3 is close to the old 1.37:1 cinema academy format, theaters suffered from a loss of viewers after films were broadcast on TV. To prevent this, Hollywood created widescreen aspect ratios to immerse the viewer in a more realistic experience and, possibly, to make broadcast films less enjoyable if watched on a regular TV set.
16:9 is the format of Japanese and American HDTV as well as European non-HD widescreen television (EDTV). Many digital video cameras have the capability to record in 16:9. Anamorphic DVD transfers store the information in 16:9 vertically squeezed to 4:3; if the TV can handle an anamorphic image the signal will be de-anamorphosed by the TV to 16:9. If not, the DVD player will unsqueeze the image and add letterboxing before sending the image to the TV. Wider ratios such as 1.85:1 and 2.39:1 are accommodated within the 16:9 DVD frame by adding some additional masking within the image itself.
Within the motion picture industry, the convention is to assign a value of 1 to the image height, so that, for example, an anamorphic frame is described as 2.39:1 or simply '2.39'.2.39:1 aspect ratio
This aspect ratio offers a very wide viewable area, and it's often used for epic movies.
2.39:1 image aspect ratio
American theatrical widescreen standard, slightly wider than the 16:9 ratio (see below). The addition of black borders is to keep the entire 2.39:1 picture, this process is called letterbox.
1.85:1 aspect ratio
1.78:1 or 16:9 (Letterbox)
The 1.78:1 ratio is better known as 16:9, this is the one for the HDTV standard and widescreen televisions. The addition of black borders is to keep the entire 2.39:1 picture, this process is called letterbox.
16:9 aspect ratio
1.33 or 4:3 Letterbox
The 1.33 ratio is better known as 4:3, the standard television ratio used by computer monitors as well. This aspect ratio is used since old 35 mm silent films. The addition of black borders is to keep the entire 2.39:1 picture, this process is called letterbox.
4:3 letterbox aspect ratio
1.33 Anamorphic Widescreen
Technique for capturing a widescreen picture on standard 35 mm film. To do so, an anamorphic lens is used during recording; stretching the picture vertically so that it fills the available film area, providing an increased quality.
Certain DVDs use this method, and since DVD players are aware of its usage, they automatically adjust the image to restore the proper aspect ratio accordingly to the TV aspect ratio used.
4.3 anamorphic widescreen aspect ratio
Pan and Scan / Fullscreen
Pan and Scan is a method of adjusting widescreen film images so that they can be shown within the proportions of an ordinary TV screen, by cropping off the sides of the original widescreen image.
This is considered destructive to the directors original vision and intentions, because it can remove up to 45% (on 2.35:1 films) of the original image, and hinder the viewer's understanding of what's happening.
4:3 fullscreen aspect ratio
The Pan and Scan method also allows the maximum resolution of the image, since it uses all the available video scan lines. This is specially important for NTSC and PAL television, that has a rather low number of lines available to begin with. It also gives a full-screen image on analog television. For this reason, Pan and Scan versions of DVDs are often called Fullscreen.