Aspect Ratio

Aspect ratio describes the relationship between the width of the screen and the height of the screen (e.g.., width : height). There are a variety of aspect ratios that are standards in film and television:

1.33:1 (4:3)—the classic TV and pre-1950's aspect ratio used in films. The reason for this ratio is debatable, but some of the first images produced in Thomas Edison's workshop was 1 inch by ¾ of an inch for viewing on a Kinescope. Many modern television and computer monitors still have this aspect ratio.

1.85:1—Wide screen formatting developed in the 1950's to provide something in theatres that wasn't available to people on their TVs at home. We often see this on TV and in videos and DVDs as "letterbox" versions with back space at the top and bottom of the image. How well this plays at home depends on the size of your TV.

2.35:1—Panavision, wider than wide screen. There are other aspect ratios including Todd-AO, which Kubrik used for 2001 A Space Odyssey, Hitchcock used for North By Northwest.

1.77:1 (16:9)—important now because this is the aspect ratio used for high definition TV. Along the lines of "letter box," some TV programs on HD TV are blocked off on the sides because they have been shot for the classic ratio.

EXAMPLES OF DIFFERENT ASPECT RATIOS (Flash Presentation) The example shows a desert image from David Lean's Lawrence of Arabia. Lean shot in wide screen to enhance the vastness of the desert spaces, which heightens the sense of majestic desolation. You'll see what happens to the image in successively narrower aspect ratios.

When Lawrence is formatted for television, it's "panned and scanned" — portions of scenes are eliminated so that the height fits the TV screen. We lose much of the sense of vastness Lean intended. Pan and scan changes films shown on TV in a variety of ways that the filmmakers didn't intend, including which characters are shown interacting in scenes, background information, and detail.

Why is aspect ratio an important consideration?

Clearly, advances in digital technologies and changes in screen sizes (particularly the move to HDTV) mean that creators don't always know how their productions will be viewed. Also, decisions must be made about what medium to shoot for in the initial production.

Multimedia may be produced for the web or other technologies (for example, PDAs, standalone presentation kiosks, cell phones) and the aspect ratios must be taken into account. The web is interesting because monitors still support the classic 1.33:1 ratio— consider the screen resolutions 800 X 600, 640 X 480, and 1024 X 768, all are 1.33:1. However, the aspect ratio of windows and sections of the screen can be manipulated in many ways by both developers and by users. Questions for developers, then, include:

How should I, or should I, control the aspect ratio of my presentation by controlling the size and shape of the window in which the material is presented?
What do I want to present and how does the choice of aspect ratio enhance my presentation?
In what ways can I divide the space on the screen to present material in different aspect ratios?

These aren't the only considerations, but they are important.