Maybe because they are products of hundreds -- or even thousands -- of talents, rather than one single creative effort, movies have always been victims of tinkering after the fact. Although a director may have the original vision about a particular picture, only rarely does he have final say as to what viewers see; even as eminent a talent as Orson Welles was plagued throughout his career by studio honchos fiddling with his work. And the outrages perpetrated on movies in the interests of sanitizing them for television are often obvious even to the uncritical eye.

One of the benefits of movies on video, in theory at least, is that we get to see what we would have seen in the theater, uncensored. Some tapes, and many DVDs, include bits that were cut out of the theatrical release in order to earn a certain rating, and there are cases of movies that have been completely re-edited for video, to achieve the director's original intentions.

But that all has to do with content. Technically, things are different: often the images we see on the small screen are a far cry from what the director or cinematographer had in mind.

It's not that there's some evil conspiracy to louse up our viewing. It's just that most movie images don't fit a normal television screen. For almost fifty years, practically all mainstream pictures have been shot in one widescreen format or another. These differ to some degree in overall screen shape, but all of them are wider in relation to their height than a 4:3 conventional TV screen. To transfer a widescreen image to television, some of it usually is missing.

The "pan and scan" process, as it's called, selects a portion of each frame containing what the transferring engineer considers to be the most important information. This chunk has to be the same shape as the TV screen, and in the more extreme widescreen systems, that can mean ditching almost half the total picture!

In the early version of this system, the final image always had the same height as the original, the transferred area simply being moved back and forth laterally to pick up the most important part of the picture. Sometimes the action shifted during a shot, and the resulting mechanical pans were only too obvious in the final product. Even worse were scenes in which, say, two actors were at opposite sides of the wide screen; as they chatted, the picture would cut from one to the other, often leaving a bit of the other actor's nose at the edge of the screen.

These blunders rarely happen with modern pan-and-scan transfers. For one thing, most movies are transferred first to digital videotape, and computer technology is used to exercise very precise control of the images. More important, perhaps, is that the engineers often have more than the theatrical widescreen image to play with.

Many movies destined to be released in one of the widescreen formats (or several) are actually shot full-frame on conventional 35mm movie film. The eventual shape of the picture is indicated by guides in the camera viewfinder, but in fact there's lots more on the film above and below the main image than will ever be see in a theater. That allows the pan-and-scan technician to "zoom out" a bit to include material at the edges of the screen, without creating black bands at the top or bottom. In extreme cases, the whole 35mm frame might be used.

While this delivers pictures free of the awkward compromises of the early years, purists argue that it does violence to the director's artistic intention by including material that was meant to be excluded and sometimes turning, for instance, close-ups into medium shots.

The alternative is the widescreen or "letterboxed" movie, in which the theatrical frame occupies the full width of the TV screen, with blank spaces above and below the image. This satisfies the desire to preserve the director's visual composition, but with most sets it produces an image that is much too small. If a movie was shot in Panavision, for instance, the letterboxed version leaves about half the TV screen empty; all of a sudden, your 28-inch set is producing an image equivalent to a 14-incher!

The only solution is much larger sets, and many buyers with deep pockets have bought projection TVs with screens of 45 inches or more. There are even a few with extended screens designed specifically for widescreen movies. And the new HDTV-ready sets are a whole new ballgame.