pan & scan

The horrible process of displaying a motion picture in an aspect ratio the director never intended.

This most often happens to display a theatrically released film on your ordinary home television screen. The observant will notice these screens are two different sizes: usually with a ratio of 16:9 or 1.85:1 for a movie and a ratio of 4:3 for a television.

To fit a large image onto a small screen, you have two choices- shrink the image to fit everything (the widescreen option), or crop the image to fit (pan-and-scan). Sometimes this technique is blatantly obvious, as in the migrane-inducing sliding pan on Michael Keaton's movie, Multiplicity, or jarring, as in most cropped, artificially cut scene with two actors at extreme ends of the frame.

More details can be found at this copyrighted page: http://www.philipwilliams.com/widescreen/panscan.htm

From the IMDB:

As the aspect ratio of movies are rarely the same as the aspect ratio of a television screen, when showing movies on TV it is necessary to make sacrifices. "Pan & Scan" refers to the technique of chopping off strips from one or both sides of the picture when displaying. The areas chopped off are typically changed on a shot-by-shot basis, depending on scene composition. The main advantage of this technique is that it allows detail to be seen, the disadvantage is that shot composition is sometimes destroyed. Contrast with letterboxing.

Sometimes during a single shot, there are important parts of the composition on opposite sides of the screen.
Often, by computer, the 'camera' continuously moves back and forth across the widescreen image in an attempt to keep the most important visuals in view.
This often brings an unnatural look to the film. Usually when real panning is done during the actual filming of a movie, there will be a subtle motion blur that is non-existant when the panning is computerized.

An even more horrible special case of this process is what we might call "scan-but-don't-bother-to-pan". That is, transfer a widescreen movie to 4:3 format as Mischa describes, but leave out the panning part, just scale the image up to the full height of the TV screen and cut off the parts that end up outside the screen, without worrying about what this does to the current scene. You can often encounter this when you pick up cheap DVD or VHS releases, or in the form of quick hack jobs for late-night cable broadcasting.

The worst example I have encountered so far is in the Scanbox DVD release of David Lynch's film Blue Velvet. This movie is originally shot in 2.35:1 aspect ratio. Can you imagine what happens when this gets cut down to 4:3 (or 1.33:1 ratio? That's right, we lose 43% of the screen width. There is a scene toward the end of this movie where Dennis Hopper is threatening Kyle MacLachlan with a gun. Well, in this wonderful Pan & Scan edition, we get to see Hopper threaten the left side of the television with the gun while talking menacingly to it, as MacLachlan is nowhere to be seen. Wonderful stuff.

For practical examples of Pan & Scan, you might want to check out IGN's visual comparison of Pan & Scan and Widescreen editions of some famous movies (Star Wars, Ghostbusters, The Usual Suspects) at http://dvd.ign.com/news/16377.html.