Larger than life. Joe McNally kept hearing and seeing that phrase in stories about people who acted heroically at the World Trade Center on Sept. 11 and afterward, and it triggered his response to the horrific attacks.

The noted Life magazine photographer began making portraits of rescue workers and survivors using the world's largest Polaroid camera.

"They loom a little larger than life," said McNally, standing among the 7- foot pictures in the exhibition "Faces of Ground Zero," on display in the busy lobby of One Market Street in San Francisco.

The figures appear in freestanding frames that let the viewer "mingle around them." "The experience is almost like meeting the person," said McNally,

who sought out and photographed a wide range of people whose lives intersected on Sept. 11: firefighters, cops, bond traders, window washers, paramedics and families of people who died.

Michael Lomonaco, who was executive chef at Windows on the World on the 106th floor of One Trade Center, sadly holds the eyeglasses he bought that morning in the underground mall, postponing his arrival at the restaurant, where 73 co- workers were killed.

Firefighter Harry Davis, a dusty bear of man who lost several comrades from Squad 18, cradles his pickax like a child. A tearful Joanne Gross holds the helmet and beloved cowboy hat of her brother, firefighter Tommy Foley, whose body was found in the rubble by her other firefighter brother, Danny Foley, also pictured.

Some have dazed or blank expressions, others convey a mix of sadness and strength, weariness and determination. Short captions tell their stories, whose cumulative effect is moving.

"I think there is a bit of shock in some of them, but there's also a really resolute quality," said McNally, 49, who was driving into New York City from his home in Hastings, N.Y., 20 miles north, when the attacks occurred. "There's a sense that 'we haven't gone away, and we're not going away.' I think that comes through, and the size of the camera complements that."

Owned by art photographer Gregory Colbert, the Polaroid is about the size of a one-car garage. The 70-pound lens comes from an old U-2 spy plane. The camera is in a lower Manhattan studio, about a mile from ground zero. Many workers came directly from the site to be photographed.

Two technicians operated the camera from the inside. McNally talked to them by radio while standing in front of the lens, directing the subjects, who stood in darkness for several seconds until he pulled off the lens cap, hit some strobe lights, then covered the lens. The image -- each cost $350 to shoot -- emerged in 90 seconds.

"There's no negative, there's no scan. It's an original piece that is life size," McNally said. "I wanted to do something that would yield some sort of worthwhile document, that would honor these people. And it seemed like the camera would be a good partner in that process."

It was a physically and emotionally exhausting process for McNally, who ran the studio 24 hours a day for three weeks straight, often sleeping there. He promised to be there whenever people showed up. All he asked was that they bring the tools of their trade.

Some would begin to talk and "go to pieces in the studio," McNally said, "talking about what they had witnessed or what they had gone through. It's impossible not to be moved. I thank God for the darkness sometimes because I would shrink back by the lens and people wouldn't see that I was a mess myself while photographing them."

The 58 portraits in this touring exhibition, presented by Time and sponsored by Morgan Stanley (the largest tenant in the World Trade Center), include one of Omar Rivera, a New York Port Authority senior systems designer, and his guide dog Salty, a yellow lab. Led by Salty and co-worker Donna Enright, Rivera walked down 71 floors of Tower No. 1 to safety.

"Many people saw what happened that day, but I heard it," Rivera is quoted as saying. "The sound of walls cracking, pipes popping, people screaming. It still echoes in my ears."

It was important to participate in this project "because it reflects what happened that day," Rivera said the other day in San Francisco, where he and Salty had come for the show's opening. "You can see people who risked their lives to save the lives of others. You have people who lost people. And there are people, as in my case, that have the great honor to be alive."

For McNally, it was a privilege to meet them all. "These are ordinary people," he said, "that, given extraordinary events, rose up and became giants. "

PHOTOGRAPHY SHOW

FACES OF GROUND ZERO: The exhibition is on display 7 a.m. to 6:30 p.m. daily except Sunday through June 7 at One Market Street in San Francisco.

E-mail Jesse Hamlin at jhamlin@sfchronicle.com.