White House photographer Michael Evans, whose memorable shot of a grinning Ronald Reagan in a cowboy hat became one of the most enduring images of the 40th president of the United States, died Dec. 1 of cancer at his home in Atlanta. He was 61.

Mr. Evans was a photographer with Time magazine in 1975 when he was assigned to cover Reagan's first run for the Republican nomination. He visited Reagan at his California ranch, where they relaxed on the porch in the late afternoon sun.

As they talked, Mr. Evans snapped the shot of Reagan in his tilted white hat, flashing a genial, lopsided grin.

"I can't exactly remember what I said," Mr. Evans told the New York Times last year, "but he must have liked it, because he had this smile that came and went quickly."

The photograph, later used for campaign buttons and as a model for a statue at the Reagan presidential library in Simi, Calif., became one of the most familiar images of Reagan, capturing the folksy, western charm that was his political hallmark. After Reagan's death on June 5, 2004, the photograph was used as the cover shot on Time, Newsweek and People magazines.

Mr. Evans covered Reagan's triumphant 1980 presidential campaign for Time, developing such a rapport that Reagan asked him to be his personal photographer. Mr. Evans had almost total independence to document the president, and many of the familiar pictures of Reagan clearing brush or chopping wood at his California ranch or having a private moment with his wife, Nancy, are his.

Mr. Evans supervised a staff that included four photographers. He estimated that they shot 37,000 rolls of film during his four years in the White House and acknowledged that 70 percent of his job was taking "grip-and-grin" photos of visitors having their moment with the president.

"Working down in the basement," he told the Los Angeles Times in 1985, "I used to wish the Russians would invade Poland so that there would be an honest-to-God crisis."

In March 1981, crisis did strike when John W. Hinckley Jr. attempted to assassinate Reagan outside the Washington Hilton. A later police reconstruction indicated that Mr. Evans, standing near the president, narrowly missed being hit in the abdomen by a bullet.

Mr. Evans captured Reagan during other tense moments, including a finger-pointing Oval Office exchange with Speaker of the House Thomas P. "Tip" O'Neill Jr. Presidential adviser Michael Deaver ordered that the photos not be released, but Reagan requested a copy for himself, which he promptly forwarded to O'Neill.

When the picture appeared on the front pages of newspapers the next day, Deaver demanded to know who had made it public, Mr. Evans recalled last year in an interview with News Photographer magazine.

"It was the 40th president of the United States," Mr. Evans said. "You're going to have to talk to him about it."

Michael Arthur Worden Evans, the son of a Canadian diplomat, was born in St. Louis and grew up in a variety of foreign postings and in Canada. He published his first photographs in Canadian newspapers when he was 15.

After attending the University of Trinity College and Queen's University, both in Ontario, he joined the Cleveland Plain Dealer in 1964 and later moved to the New York Times and Time.

"Mike was a skilled photographer, but his genius was storytelling," Donald R. Winslow, editor of News Photographer, said. "You can see his eye and his intellect in picture after picture and his integrity in the choices he made."

In 1982, searching for a different outlet for his work, Mr. Evans undertook an ambitious effort to document the Washington power elite. Nearly 600 people, including Supreme Court justices, congressmen, socialites, journalists, the vice president and even a Capitol janitor, sat for stark black-and-white portraits, which were exhibited at the Corcoran Gallery of Art in 1985 and reproduced in a book. He later helped organize a Corcoran exhibition on the homeless.

Mr. Evans left the White House in March 1985, when Donald Regan replaced James A. Baker III as chief of staff. Mr. Evans returned to Time magazine for several years before moving to Atlanta in 1989 to become photography editor of the Atlanta Journal-Constitution. He later formed his own company to develop computer software, including a digital cataloguing system called "Iron Mike" that is used by newspapers, magazines and picture agencies around the world.

He also worked with Kodak to design digital cameras. He ended his career as chief technical officer of ZUMA Press, a photography agency.

His marriage to Linda Anne Forde ended in divorce.

Survivors include his wife of 22 years, Story Shem Evans of Atlanta; four children from his first marriage; two daughters from his second marriage; a brother; two sisters; and four grandchildren.

Mr. Evans, who said he never had a political discussion with Reagan, described his job as "more like being a valet than like the secretary of state. . . . Yes, we have a personal relationship, but we both have a reason to be there and have a job to do."

Michael Evans peruses shots he took during his long career. Some of his last projects were forming a company to develop computer software and working with Kodak to design digital cameras.As White House photographer, Evans had almost total independence to document President Reagan, from state visits to quiet moments with wife Nancy to political confrontations.Evans's iconic photo was shot in 1975 during Reagan's first run for the presidential nod.