Picked apart during castings for her teeth, or her thighs, Ms. Porizkova was terrified. “Every job felt like it was going to be my last,” she said. Propped on such flimsy scaffolding, her sense of self was compromised.
“What people called sexual harassment, we called compliments,” she said. “When a 16-year-old is flattered by a man pulling out his penis in front of her, that’s noteworthy.” 
Not all of Mr. Greenfield-Sanders’s subjects were as forthcoming. He recalled that Ms. Rossellini was initially offended by “Ageless” (the working title of the film). She thought it smacked of misogyny. Beverly Johnson, the first black model to grace a Vogue cover, in 1974, had misgivings, intensified, she confided in a phone interview, when Mr. Greenfield-Sanders showed her early images. “I was like, ‘You’re going to retouch this photograph, aren’t you?’ ” she said. “ ‘We’re supermodels. You’ve got to retouch.’ ”
The filmmaker’s warts-and-all approach angered some of her peers as well, Ms. Johnson said. “We were all calling each other on the phone, asking: “Can you believe this guy? Who does he think he is?’ But after awhile, we all felt kind of comfortable in it.”
That they did is a testament to Mr. Greenfield-Sanders, whose mild-as-a-curate features and studiedly unassuming manner tend to foster trust. Like his subjects, he is aware of his own aging. “At Sundance we had to pose for these press pictures,” Ms. Johnson recalled. “I looked at him and noticed, he’s posing. He’s like the fourth model in the group, very aware of his looks.”
“Everybody is sucked into that vortex,” she added. The hairdressers, the photographers — no one is immune. “We all live in a bubble, a place like no other.”
By nature or necessity, though, the filmmaker remains mostly untouched. “There is a sweetness to his character,” Ms. Nevins said. “He laughs at himself.” Dolores Hart, who threw over a movie career in the 1960s to become a nun, was one of those who gained a sense, Ms. Nevins said, “that what’s in front of his lens is the most important thing in the world at that moment.”
Mr. Greenfield-Sanders is cannily aware of his strengths. He sat chatting in the kitchen of his home and studio, a converted rectory on the Lower East Side of Manhattan, where most of the film was shot. The rooms are hung with artworks, most prominently the large figurative canvases of his daughter Isca Greenfield-Sanders.
“I am very, very tuned into people,” he said. “If something’s wrong, I can sense it from the moment they walk in the studio.” It is a skill he picked up early. Commissioned to shoot Orson Welles, Mr. Greenfield-Sanders, then in his 20s, tried for a conversational icebreaker, asking him, “What’s your favorite film?
“I don’t play games like that,” came the snarly reply.
“What I learned is that I wasn’t there as a tourist,” Mr. Greenfield-Sanders said. “I was there to make him comfortable.”
“People will tell you their stories if you give them a chance,” he added.
Those tales can be amusing. Jerry Hall grew up in Texas, where she worked in her teens at a local Dairy Queen. Her mother made her clothes, she told the filmmaker, though not all of them. “We used to get the Frederick’s of Hollywood catalog,” she said. “All that snakeskin and satin,” she said, seemed to her the pinnacle of chic, suitably glamorous for a trip abroad. “We thought Paris was like that,” she said.
Other stories are disturbing. Lisa Taylor, perhaps best remembered for lounging, legs parted suggestively, for a Helmut Newton photograph, succumbed to the lure of cocaine. “I was so insecure that I needed to do it,” she said. “It made me feel like I had something to say, that I was worthy of being photographed, that I was somebody.”