Through the magic of computer-generated digital imaging, the pyramid moved, not in space, but on the Geographic's cover, where its apex was electronically shifted to make it into the magazine's yellow cover frame.

"The effect was the same as if the photographer had moved over a few feet," the Geographic's editor Wilbur Garrett wrote to a complaining reader after the New York Times reported the magazine's transgression.

How much did the use of a telephoto lens move the pyramids? Garrett asked. How much did the color change because of a filter? Were the camels there naturally or were they brought there for a picture?

Garrett's point — that reporting and photojournalism have always created their own views of reality — doesn't eliminate the radical shift digital image processing computers have made in the reality of today's news photography. Indeed, their almost magical abilities — to create effects, to correct mistakes and to save money -- are fast making the machines indispensable in post-production shops. "At first, about 80 percent of the time our equipment was used for special effects," says Steve Mayer, chairman and chief technical officer of Digital FX in Mountain View, California. "Now, it's mainly used to touch up reality. An actor's hair is out of place or a product's label is blue instead of red. The president of a major corporation gave a speech which was taped, and part of his apparel wasn't zipped. That was fixed in the computer."

The machines can subtract as easily as they can add. In one case, a director had just spent $400,000 taping a candy commercial featuring a family and its cat. Suddenly, for legal reasons, the cat couldn't be used. Instead of reshooting the costly ad, the director turned the raw footage over to a computer. The cat simply disappeared from the finished commercial.

But the desire to add to or subtract from reality has also reached as far as the Reagan White House, which erased Oliver North from several official Oval Office photos before publicly releasing them.

In fact, although the television industry is using digital imaging technology routinely, almost no one has considered what it means now that pictures can lie as easily as words. "Once this new technology gets out there," says Thomas Wolzien, vice-president of editorial and production at NBC Television News, "we're going to have a hell of a time telling what's real and what's unreal." Adds David Zeltzer, a leading MIT researcher in computer animation, "What's going to happen to electronic newsgathering when the validating function of videotape no longer exists? Television will no longer be a verification medium. Who's going to control that?"

Magic Manipulator

Priced below $500,000 — not at all beyond the means of a successful studio or production lab — video-imaging computers are now regularly doing things that were too costly or technically impossible even three years ago. And this kind of manipulation is no longer even the exclusive province of the well-heeled specialty lab. Software recently released for the Apple Macintosh desktop computer gives almost anyone identical power over pictures.

Now, anyone from a spouse to a world leader can be "photographed" in places they never visited or in incidents that never took place. "After a divorce you can erase your ex-mother-in-law from all your family photos," Wolzien says. "You could formulate a picture of yourself addressing the United Nations General Assembly without ever leaving your den."

Technology's ability to change images into electronic information has destroyed the photograph as a reliable record of reality.

"What can be done to commercials and situation comedies can also be done to documentaries and news footage," Wolzien warns. "Video retouching could have kept the late Soviet General Secretary Chernenko looking alive forever, changing his clothes and surroundings. Working from existing videotape, a good video artist could make Chernenko visit with people who were photographed long after his death. Background from one picture can be combined electronically with people from others. Heads of state could be shown greeting each other at an airport even though one, or both, were never really there." Computers could easily concoct a tale of a presidential candidate smiling and chatting with men wearing Klan robes or Dan Quayle on a shadowy street corner whispering to a prostitute.

Ease of Alteration

Videotape editing was always done numerically by machine, not by hand. Artistic control was lost. Now, after a few hours' tutoring with a computer, even a novice can edit videotape visually to professional standards.

The footage is run through a videotape recorder that's connected to a computer. The computer digitizes each frame — turns it into electronic representations of digits — and stores it in the computer's memory. Images can be called up on the computer's video screen frame by frame or in a series of several at a time, like a strip of film. The "composer," as the computer jockey is called, draws and points with a pencil-like wand on an electronically-sensitive slate to tell the computer what to do. Images can be shrunk, zoomed, moved or manipulated almost without limit. If the effect isn't quite right, the composer simply tells the computer to undo it and tries again.

With today's equipment, actors can be added to scenes they never inhabited, or deleted from scenes in which they appeared; a parking lot can be transformed into a meadow, or a river can become a freeway. The changes are virtually seamless, quite possibly undetectable even by the engineers who create the effects.

By putting image-making decisions into the hands of editing technicians, "these machines raise legal and ethical questions that range from the nature of copyright laws to the breadth of the First Amendment," an engineer commented.

Retouching Reality

As the National Geographic cover demonstrates, newspapers and magazines have been wrestling, not always successfully, with these questions for nearly two decades since digital manipulation of still photographs was pioneered in the early 1970s. Commerce was quick to make use of the technology. The colors and appearance of products and models in photos are now routinely tweaked through digital reprocessing to suit the whims of their purveyors. "Without announcement, advertising has become completely illusory," notes Stewart Brand, author of The Media Lab: Inventing the Future at MIT and former publisher of The Whole Earth Catalog. "There was never a point — a scandal or something — that let people catch on that catalogs and ads are often very far removed from representation of reality in photographic images."

The only real safeguard preventing similar manipulation in news images is the degree of integrity the technology's users bring to it, Mayer thinks. "People in the industry have been particularly sensisitve in this area. The downside of abusing this kind of public trust is so great that most people aren't willing to risk it. The use of this equipment is built on a tacit ethical understanding that doesn't allow users to go too far too fast."

For the moment, news producers would do well to learn from National Geographic's mistake: Entertainment is one thing, but people like their reality straight. They won't tolerate reality-fiddling from those they trust for accurate information about reality. ABC News learned that the hard way when for its evening report it simulated alleged spy Felix Bloch handing his attaché case to a Soviet agent.

Viewers in search of honest pictures are squeezed between two unhappy truths: They can't tell a falsified image simply by looking at it, and they can't trust news organizations to tell them up front when an image has been tinkered with.

The Dangers are Obvious

The major question about the technology's implications is a basic one: How much computerized fiddling are we willing to accept, and from whom? "Don't trust a photograph if anything is riding on it," says Loren Carpenter, a senior scientist at Pixar, a San Francisco-based computer graphics company, and formerly a specialist in synthetic photography at Lucasfilm, the California movie studio that produced the Star Wars trilogy and other special effects films. Brand agrees that this is in "the thick of how we'll think about communication and 'truth' and editorial responsibility — the broadcast fabric of civilization."

Gradually, Mayer thinks, viewers will become more sophisticated in judging and evaluating video fare. "People establish a visual language and the rules for understanding that language," he says.

"With this new technology, there might be ambiguity in some cases. But sophistication ratchets with time. As rules change and evolve, they're absorbed throughout society very quickly. Not as quickly as technology advances, though. By the new century, computers will be able to create scenes out of digits, people them with animated stills of actors and synthesize voices to go with them to create personal movies.

"We don't know what all these changes are going to mean to the industry or to its audience," Zeltzer says. "But we're going to find out sooner than any of us are really prepared to."