The shooter

''Isn't this nice in here?" James Nachtwey asks, his voice quiet and even. A slow sweep of his arm takes in his room at the Ritz-Carlton Boston. ''The light's so beautiful this morning, and that window has a view of the Public Garden."

Certainly, it's worlds away from the places Nachtwey (pronounced NOCHT-way) has chronicled for 25 years -- Central America, Bosnia, Somalia, Rwanda, Chechnya, Kosovo, Sudan -- places that have made him known as this era's preeminent photographer of war and disaster.

''Jim consistently takes great photos," says Jeffrey Keough, director of exhibitions at Massachusetts College of Art who organized a 1997 Nachtwey show, ''Ground Level."

''He's a phenomenon," Keough says. ''I don't know how he does it. If you believe in the power of images to move people, then you believe in Nachtwey. He goes around the world as a true witness."

Nachtwey, 57, has been a contract photographer at Time magazine since 1984. His work has also appeared in numerous other publications: National Geographic, L'Express, Stern, The New York Times Magazine. Two collections of his photographs have been published. They bear titles that are simultaneously melodramatic and precisely accurate: ''Deeds of War" and ''Inferno."

He was in Boston earlier this month to deliver the annual Karsh Lecture in Photography at the Museum of Fine Arts.

The sheer quality of Nachtwey's work accounts for much of his renown. He's a six-time winner of the National Press Photographers Association's Photographer of the Year award and eight-time winner of the University of Missouri's magazine Photographer of the Year award.

''The temptation to say there's no one like Jim in photojournalism is very great," says Willis E. Hartshorn, director of the International Center of Photography, in New York. ''In that world, he definitely sets the standard."

Nachtwey's persona also contributes to his reputation. ''He is very charismatic," says Richard Whelan, a historian of photography and biographer of the most legendary photojournalist of them all, Robert Capa.

Some of that charisma comes from Nachtwey's movie-star good looks, which are three parts Sam Shepard to two parts Pierce Brosnan. He's even been the subject of a movie, the Academy Award-nominated documentary ''War Photographer." The straightforwardness of the title suggests how much Nachtwey dominates his profession. He is the specimen who now defines the genus.

Yet Nachtwey turns upside down any Hollywood stereotype of the photojournalist as cowboy or ''adrenaline junkie," a term he disdains. He dismisses any idea that his work is glamorous. Several times he's nearly been killed, most recently in Iraq, in December 2003, when a grenade was tossed into the Humvee he was riding in.

Grave, centered, almost otherworldly, Nachtwey is the polar opposite of Dennis Hopper in ''Apocalypse Now" or James Woods in ''Salvador." He speaks slowly, every word deeply considered, with an air of preternatural calm that borders on the spiritual.

Nachtwey, who's never married, averages eight months a year on the road. Even in New York, where he lives, work has a way of finding him. He arrived back on the evening of Sept. 10, 2001, from an assignment abroad. His studio is just a few minutes from the site of the World Trade Center. The next morning he was on hand to record the collapse of both towers. ''It's not like I have another life, and I do this," he says of photojournalism. ''This is my life."

''Jim is like a kind of priest," says Keough, ''He's a dinosaur: one of the true believers."

It wasn't art -- or adventure -- that drew Nachtwey to photojournalism, but moral engagement. ''I'm not the kind of photographer who carries a camera with me everywhere I go," he says. ''When I use a camera it's for a reason."

Nachtwey grew up in Leominster. He speaks with visible pleasure about taking the train into Boston to watch the Red Sox and, especially, Celtics. ''God, it was a great era, with Bob Cousy and Bill Russell -- fantastic. I was a passionate Celtics fan."

What Nachtwey wasn't passionate about was photography. Asked if as a teenager he didn't have a Kodak Instamatic or Polaroid Swinger, he shakes his head, ''I had no clue about photography."

At Dartmouth, Nachtwey majored in art history and political science. What attracted him to photography was the work of photojournalists chronicling the civil rights movement and Vietnam War. ''It was in the '60s," he says. ''I wanted to do something with a social purpose."

After graduation, he worked in the Merchant Marine, traveled through Europe, then took a job in an editing room at NBC News, in New York. He worked as an assistant to Boston photographer John Goodman and began taking his own pictures. He was hired as a photographer by The Albuquerque Journal. In 1980, he returned to New York to freelance and got his first foreign assignment, Northern Ireland, a year later.

The ICP's Hartshorn likens Nachtwey to the great Brazilian photographer Sebastiao Salgado. More often, he's compared to Capa (Nachtwey has won the Overseas Press Club's Robert Capa Gold Medal four times). The basis of the comparison isn't just excellence and shared subject matter. It's also level of commitment.

Like Capa, Whelan says, Nachtwey ''goes to conflicts about which he cares, conflicts about which he's willing to risk his life. It was Capa who said he was simply unwilling to cover a war he didn't care about deeply. And Nachtwey is that way, too, absolutely."

A less-noted affinity is between Nachtwey and Henri Cartier-Bresson. It's most apparent in Nachtwey's phenomenal eye for composition. Photojournalism is about the presentation of dynamic images, while the greatest photojournalism is about the organization of dynamic images. Cartier-Bresson set an unmatched standard for such organization, but one Nachtwey approaches. He has written that when he decided to be a photographer he enlisted Cartier-Bresson as a ''virtual teacher," looking at books of his images for ''hours at a time." Once he could afford to buy art books, Cartier-Bresson's were the first he owned ''and the most cherished."

''When I'm shooting," Nachtwey says of his gift for composition, ''it's a natural thing for me. By now, I'm so trained to always be dealing with visual phenomena, I'm composing something all the time."

The corollary to seeing the right thing is being in a position to see it. Past a certain point, luck becomes a form of talent. Nachtwey's arrival in New York the day before 9/11 is just the most startling example of this.

''He's really attuned to history as it unfolds," Hartshorn says of Nachtwey. ''He has an intuition about being at the right place at the right time. That's very separate from any photographic or visual skill. There's a sense in which if you arrive somewhere, and Jim's there, you're in the right place."

Nachtwey's most recent assignment was for Time's year-end Persons of the Year issue, photographing Bill and Melinda Gates as they investigated poverty in India and Bangladesh for their foundation. ''It was a very different kind of assignment for me," he says. ''It was a one-off, really."

Nachtwey says he can't imagine turning to other subjects from the ones he's devoted the past 25 years to. He also says he can't imagine retiring any time soon. ''I'm not lying awake at night thinking about it," Nachtwey says.

''There are physical obstacles that you have to overcome and there are also emotional obstacles. I suppose the more sensitized you are emotionally, sometimes it becomes harder. But if you have a sense of purpose about it, you try and transcend. But at the same time you see more, you're aware of more, it means more."

Mark Feeney can be reached at mfeeney@globe.com.