Richard Avedon, whose high-profile fashion photography of the 1950s and 1960s was eclipsed in later years by his own distinctive and evocative portraits of the known and unknown, died yesterday of a brain hemorrhage at a hospital in San Antonio, where he was on a photo shoot for the New Yorker. He was 81.

Avedon's magazine project, tentatively titled "On Democracy" and scheduled to run the week of the election, started out with pictures taken at the Democratic and Republican national conventions, where he had made portraits of Karl Rove, James Carville, former president Jimmy Carter and Illinois Senate candidate Barak Obama, among other delegates and speakers.

Avedon's stark and unsettling portraits have appeared in America's most prestigious magazines and museums for the past half-century. He was considered the world's most famous, and perhaps richest, photographer.

His celebrity subjects over the years included Pablo Picasso, Andy Warhol, Frank Lloyd Wright, Marilyn Monroe and hundreds of others. They were, as one photographer described them, "pinned like butterflies" on a seamless white background, staring at Avedon's big 8-by-10 Deardorf camera.

Ordinary Americans also were frequently the subject of his arresting, at times disturbing portraits.

The New Yorker project had grown in recent weeks to include ordinary people, including gun collectors in Winnemuca, Nev.; two homeless men in Reno, Nev.; soldiers at Fort Hood, Tex., and burn victims from the war in Iraq being treated at Brooke Army Medical Center in San Antonio. These were people whose lives were affected by the decisions of political leaders he portrayed at the Boston and New York conventions this summer.

Avedon began experiencing headaches and blurred vision while shooting tanks Thursday at Fort Hood and was unable to continue the project.

He also had scheduled shootings for this week in Washington of Secretary of Defense Donald H. Rumsfeld, Federal Reserve Chairman Alan Greenspan and Chief Justice of the United States William H. Rehnquist.

For decades, Avedon was one of the nation's most celebrated fashion and portrait photographers. The way he captured women made several of them rich and famous. His early models included Dorian Leigh, Dorothy Horan ("Dovima") and, perhaps most famous of all, Suzy Parker. He later worked with Lauren Hutton, Twiggy and Brooke Shields.

He was the first staff photographer hired by the New Yorker, a magazine that ran photographs only rarely before Tina Brown took over as editor in 1992. His 1963 portrait of Malcolm X was the first full-page photograph published in the magazine.

Avedon described "a separation between fashion and what I call my deeper work," in a 1974 Newsday interview. "Fashion is where I make my living. I'm not knocking it; it's a pleasure to make a living that way. . . . Then there's the deeper pleasure of doing my portraits. . . . I consider myself to be a portrait photographer."

Richard Avedon was born in New York City. His father, Jacob Israel Avedon, was a Russian Jewish immigrant who grew up in a New York orphanage and later operated a successful retail clothing business called Avedon's Fifth Avenue.

As a boy, Avedon was casually interested in photography and kept a scrapbook of photos that his father consulted for the dress business.

He and a cousin sometimes sat outside the service entrance of their grandparents' apartment listening to music coming from the apartment of another of the building's residents, the famed Russian composer-pianist Sergei Rachmaninoff.

"Maybe that's where I learned about discipline and what's beautiful about rigor, what's compelling about craft, those months listening to him going over and over one phrase," Avedon told a reporter.

He dropped out of high school at 17 and found a job as an errand boy with a small New York photographic company, even as he dreamed of being a poet. He joined the Merchant Marine in 1942, and with a Rolleiflex camera his father had given him as a going-away gift, he applied to the Merchant Marine's photography branch.

When he left the Merchant Marine in 1944, he found work with Bonwit Teller, one of New York's most fashionable department stores. About a year later, he took a portfolio of his work to Harper's Bazaar. He was hired for the magazine's Junior Bazaar section.

At Harper's Bazaar, Avedon set about changing the look of fashion photography. He moved his models out of the studio -- to the beach, the zoo, a circus, the waterfront, a junkyard, the pyramids of Egypt -- and had them drop the frozen-faced mannequin look. When he was in the studio, he eliminated props and backgrounds, an approach he would use to singular advantage in years to come.

More than 80 portraits of the famous -- including Mae West, Bert Lahr, Marian Anderson, Louis Armstrong and Charlie Chaplin -- were compiled in the 1959 book "Observations" (Simon & Schuster), with comments by Truman Capote.

Although his portraits had been represented in various group shows over the years, including Edward Steichen's "The Family of Man" at New York's Museum of Modern Art in 1955, it was a 1962 Smithsonian Institution exhibit that began the shift in how the critics viewed his work.

By the mid-1960s, Avedon was the hottest fashion photographer in town. Revlon, DuPont, Pabst, Maidenform, Cartier and Douglas Aircraft were among the high-profile companies clamoring for his signature look.

Avedon served as staff photographer with Harper's Bazaar from 1946 to 1965. He worked in the same capacity for Vogue from 1966 to 1970.

"In a field where something new and flashy is needed every season, Avedon was at the top of his game for over 40 years," said Arthur Ollman, director of the Museum of Photographic Arts in San Diego. "The way we see fashion, and ultimately the way we have pictured women, was totally altered by Richard Avedon. And it was not just any 40 years, but it was the 40 years in which feminism came into the public consciousness."

In the summer of 1970, the Minneapolis Institute of Arts mounted a comprehensive exhibit of Avedon photographs, said to be the largest exhibit ever devoted to the work of a single photographer. A highlight of the show was a collection of portraits of the Chicago Seven defendants in the 1969 conspiracy trial of antiwar activists.

Pamela Maffei McCarthy, Avedon's editor at the New Yorker, said portraiture is a tricky business. "It's very difficult to go behind the facade," she said. "He was able to get the inside out, and uniquely so. He was able to expose character."

Beginning in the late 1970s, Avedon spent five summers trekking across 17 states to photograph more than 700 people who, in his view, represented the American West.

Commissioned by Fort Worth's Amon Carter Museum, "In the American West" offered 120 powerful and affecting portraits of "ordinary, hard-working people." Photographed in harsh light that exposed every sag, wrinkle and blemish, they included miners, drifters, carnies, bartenders, waitresses and oil field roustabouts. Perhaps the most memorable was a pale, nearly hairless beekeeper with thousands of bees forming dark free-form tattoos on his bare torso.

In Richard Avedon's West, there was no John Wayne, no Gary Cooper, no Marlboro Man. "This is about a class," he told The Washington Post. "It's about very hard times, very long hours, hard work, unrewarding lives with very little expectation of upward mobility."

Laura Wilson, a Dallas photographer who worked for six years as Avedon's assistant on "In the American West" and the latest New Yorker project, described him as "beyond extraordinary, when I first met him and in these last two years. There was enormous energy, enormous enthusiasm and an enormous obsession with the work itself."

In a 2002 exhibit, the Metropolitan Museum of Art offered 180 portraits Avedon had done from the late 1940s through the end of the century. Curator Maria Morris Hambourg said, "By dint of progressive challenges to himself, Richard Avedon has not only distilled photographic portraiture to its irreducible core, but has also produced an extended meditation on life, death, art and identity."

Avedon's final New Yorker project was in some ways an updating of a 1976 Rolling Stone assignment, called "The Family" and shot during that year's presidential campaign.

"He was interested in the politics of the moment. He wasn't a nostalgist," New Yorker editor David Remnick said. "He saw this as a serious political moment, and he wanted to get in the middle of it in the way that he could."

The photographs will run as scheduled and will include color and black-and-white images.

"He had the energy of five hummingbirds," Remnick said. "We were getting an enormous amount of new work right up until this morning."

Avedon married and later divorced Dorcas Nowell, a model, who became known professionally as Doe Avedon. He married Evelyn Franklin in 1951 and later separated.

Survivors include a son from the second marriage, John Avedon of New York City, and five grandchildren.

In 1974, Mr. Avedon told Newsday: "I can see myself as a very old man in a terrific wheelchair. Only, I won't be photographing the tree outside my window, the way Steichen did. I'll be photographing other old people."

As it turned out, the octogenarian photographer was shooting Army tank drivers, injured soldiers and, yet again, ordinary people in the American West and Southwest.

"He had the greatest life for doing what he wanted to do," said Wilson, who was with him when he lapsed into a coma. "And to do it this way, where he was going full tilt to the very end, that's how he would have wanted it."

Richard Avedon's 1981 portrait of beekeeper Ronald Fischer was part of his chronicle of the hard-working American West.Avedon portrayed fashion, the famous and the ordinary.Avedon did a group portrait of the Chicago Seven in 1969, when they went on trial: Lee Weiner, left, John Froines, Abbie Hoffman, Rennie Davis, Jerry Rubin, Tom Hayden and David Dellinger.Avedon, who liked to take fashion shoots beyond the studio, put the model Dovima among the elephants in 1955.