After “The Black List,” “The Latino List” and “The Out List,” Timothy Greenfield-Sanders is chronicling his biggest societal subset yet. ¶ “The Boomer List,” which just opened at the Newseum for a nine-month run, is a series of photographic portraits, accompanied by a documentary that aired on PBS’s “American Masters” and a DVD and a coffee table book that came out this month. ¶ The project celebrates the events, accomplishments and challenges that faced the nation’s largest generation — born between 1946 and 1964 — on the occasion of the youngest of the group turning 50 this year.

“I’m proud of being a boomer,” Greenfield-Sanders says by phone from New York.

But, he adds, “I’ve always hated the term baby boomer. . . . It’s something that seems to infantilize the members of the group. I’ve always thought it was a period of tremendous accomplishment.”

If it sounds like a dream collection of cover shots for a year and a half of the AARP Magazine, you are close. “The Boomer List” was commissioned by AARP after an executive saw Greenfield-Sanders’s 2012 HBO film, “About Face: Supermodels Then and Now.”

AARP’s Myrna Blyth, looking to the 50-year landmark for the youngest in the group, asked him, “Do you have thoughts on boomers?”

Portraits of people born each year of the generation would make a nifty “Boomer List.”

His challenge then was represent each year with a balance of races, gender, culture, commerce, sports and activism, celebrities and non­celebrities.

Filling all that criteria in 19 slots, representing 76 million people, was like “working on a Rubik’s cube in the dark,” Greenfield-Sanders says.

“There were certain categories we wanted someone from, and Vietnam is a good example,” he says. “There are only a certain amount of veterans left, and those are the early years.”

His choice was Tim O’Brien, who was born in 1946 and chronicled the era in such much-hailed books as “The Things They Carried” and “Going After Cacciato.”

With O’Brien representing 1946, Greenfield-Sanders says, “you’ve just eliminated George Bush, Patti Smith, Bill Clinton and Diana Van Furstenberg. You see what a juggle that is.”

“You really had to decide, are you going to give up Bill Murray and Arianna Huffington for Steve Wozniak — that kind of choice,” he says. “I won’t say it was ‘Sophie’s Choice,’ but it was a difficult choice.”

Among those who ended up in “The Boomer List,” sitting for portraits and sharing their stories in the documentary, are well-known faces such as Samuel L. Jackson, Billy Joel, Tommy Hilfiger, Deepak Chopra, Amy Tan, Eve Ensler, Maria Shriver, Kim Cattrall, Rosie O’Donnell, Steve Wozniak and John Leguizamo.

But there are also shots of Erin Brockovich, AIDS activist Peter Staley, photographer David LaChapelle, IBM chief executive Virginia Rometty, NASA executive Ellen Ochoa, and Julieanna Richardson, executive director of the HistoryMakers, the nation’s largest collection of African American video oral histories.

But for a D.C. exhibit that hangs a block away from the U.S. Capitol, there are no politicians.

“I stayed away from politics,” Greenfield-Sanders says. “The reason I did is because the rules of PBS are if you have one side of the aisle you have to have the other. That would have been two people out of the 19 devoted to politics, and I thought, in the end, let’s just drop them.”

Creating “The Boomer List” took about a year, he said. “Famous people were very hard to get.”

Scheduling sessions in his East Village studio was time-consuming. “I really prefer in my own studio in New York,” he says. “But in some cases we’re in a hotel room, if that’s what it takes.”

The process was usually to do the filmed interview first. “Getting to know that person for an hour or so, listening to that person talk, it’s very helpful,” Greenfield-Sanders says.

For the portraits, there was a sort of dress code.

“I encourage people not to wear short sleeves, and I encourage a solid, darker color so you’re really concentrating on the face,” he says. “Short sleeves are hard because your eyes are pulled to the flesh tones.”

As far as positioning the person, Greenfield-Sanders says he had to consider what the other subjects of the exhibit would be doing.

“Look, everyone looks good with their arms folded,” he says. “But I can’t have 19 people there folding their arms. So when John Leguizamo offered to take his pants off, I jumped at the opportunity.”

For each pose, he says, “I tried to change it up as much as possible, and yet at the same time be true to the person. You don’t want someone in a pose just because you need a new pose. You want someone to be comfortable in the way they’re standing there.

Greenfield-Sanders knows what he wants once he sits a subject down. “You have to read quickly the mood, you have to look at the face and see which is the side that’s going to work. Everyone has a better side — most of the time, it’s the person’s left side. I’m not sure why.”

He uses a large-format Deardorff camera from the 1940s, affixed with newer lenses about 25 years old.

“For 20 years I’ve shot with an 11-by-14 camera, shooting black-and-white film,” he says. “When they discontinued that film in about 2000, I switched to 8-by-10 color. I’ve been shooting that ever since.”

Instead of keeping the motor drive revving, Greenfield-Sanders says, “I only expose a handful of frames. I don’t shoot a lot. Most photographers today shoot digitally and they have no limit to what they can shoot. But that’s not portraiture to me.” Instead, he likens it to what Truman Capote once said about the writing of Jack Kerouac: “That’s not writing, it’s typing.”

Some of his work is informed by his art history major at Columbia University, but what got him into portrait photography in the first place was volunteering to take shots of visiting dignitaries at the American Film Institute, where he went to learn filmmaking in 1975.

After a session with Alfred Hitchcock, who told him, “Your lights are in the wrong place, young man,” Greenfield-Sanders was invited to his studio to talk to his lighting people.

“And Bette Davis, when we had her in the seminar, I leaned out to shoot her portrait and she said, ‘What . . . are you doing shooting from below? You never shoot from below!’ And I said, ‘Well, why?’ And she said, ‘It’s unflattering.’ ”

Davis told him she’d tell him all about photography if he would be her driver for a week.

“We talked about George Hurrell, the great photographer of Hollywood, and she really helped me a lot,” Greenfield-Sanders says. “So I became interested in photography at the feet of all these great Hollywood directors and producers and actors, and learned it that way. And by the time I finished AFI, I was more interested in portraiture than I was in film.”

He got back into film when he made the 1998 bio “Lou Reed: Rock and Roll Heart” for PBS and has since learned to combine film and portraiture.

The Newseum has surrounded the set of portraits with its own timeline, illustrated by period magazine covers and coveted items of the generation, such as Barbie dolls and a Walkman. There’s also a collection of scents to sample from the generation, including baby powder and incense.

Having his portraits hang at the Newseum is a big deal, Greenfield-Sanders says.

“Every photographer is or should be excited about a museum show, and I am very excited about this one,” he says.

“I really love these opportunities because it’s a way for the world to see your work. You show in a gallery and it’s wonderful, but it’s very limited. It’s a tiny art world that sees what you do, and museums are bigger and broader and more inclusive.”

Catlin is a freelance writer.

“The Boomer List” continues at the Newseum, 555 Pennsylvania Ave. NW, through July 5. Call 202-292-6100 or visit www.newseum.org. “The Boomer List” film on “American Masters” is streaming at www.video.pbs.org.