Whenever Nadia Hallgren was asked about the highlight of her filmmaking career, she always had an answer at the ready: shaking Michelle Obama’s hand.

It was just a quick gesture — a polite thank you offered from the then first lady to the camera crew who had been trailing her for a CNN special on a 2016 trip to Liberia. But the cinematographer had long felt a connection to the Obamas, viewing their eight years in the White House as “an incredible time in America” that Hallgren “experienced very deeply and emotionally.”

So when Hallgren received a call from the couple’s company, Higher Ground Productions, asking if she’d be interested in shooting a documentary about Michelle Obama’s upcoming book tour, she immediately started cramming. She had three weeks before she’d take a train from her home in Brooklyn to Washington to interview with Obama in person. So Hallgren searched YouTube to watch her speeches, listened to her voice on podcasts and reread both of former President Barack Obama’s memoirs to learn about the couple’s relationship.

But when she eventually turned up at the D.C. office in the fall of 2018, she couldn’t ground herself. Michelle Obama’s office, softly lighted and covered in beautiful artwork, felt ethereal.

“It looked like a dream, so I kept wondering if I was in one,” Hallgren recalled from an apartment in Rockaway Beach, N.Y., where she has been spending the shutdown. “She gets up and starts walking in my direction — and I’m very short, so she kind of towers over me. I extend my hand to shake her hand, and in my nervousness, we had this very awkward, intertwined-finger handshake. I was like, ‘Oh my God, I’m messing this up already!’”

But Obama — who declined to be interviewed for this story — wasn’t put off. She suggested they hug instead, and they spent the next 30 minutes sharing stories about their respective upbringings. By the time the meeting was over, Hallgren had the job.

Except it still wasn’t entirely clear what the job was. At the time, Hallgren had no idea that the footage she’d been hired to collect would end up in “Becoming,” the Netflix documentary she also directed that debuted on the streaming platform last week. Executives at Higher Ground — which has a multiyear deal to produce films and series for Netflix — said the material might well just live in Obama’s personal archive.

“I looked at it like this: The bright side would always be spending a bunch of time with Mrs. Obama and having an incredible experience, even if no one ever knew about it,” said Hallgren, who worked as a cameraperson on docs including “RBG” and “The Hunting Ground,” as well as “Oprah’s Master Class.”

But after reviewing some early footage, the filmmaking team agreed that it had the potential to make a feature-length movie. Hallgren ultimately trailed Obama on 23 of her 34 tour stops, filming her in conversation with the likes of Stephen Colbert and Gayle King. She recorded community events with high school students and church groups, observing Obama’s effect on people of color in the U.S. But she was also able to capture the behind-the-scenes machinations of a massively famous person’s life, revealing the security procedures, fashion consultations and hotel stays that make up Obama’s day-to-day.

“The truth is that when we were on the tour, there were no parameters,” Hallgren said of the restrictions placed on her. “On the first day of filming, I went through certain channels so that I could ride in the car with her. I go to the car to load in, and there’s an agent outside the door. I said, ‘Hi, sir. I will be riding with Mrs. Obama today in the motorcade.’ And he’s like, ‘Are you sure about that? Give me one second.’ He turns around (to check) and he’s like, ‘You know, this never happens,’ and he opens the door and helps me load in, and I’m like, ‘Wow. Just to get in the car.’”

During the first weeks of the shoot, Hallgren was intimidated. She wanted to make the film feel intimate, so she knew she couldn’t remain in the corner of a room using a long lens. Instead, she had to be physically close to Obama — a task that initially required some positive self-talk.

“I had to tell myself, ‘You cannot be scared. Get that courage,’” Hallgren said. “Because when you’re making a film like this, every moment is valuable. I’m not the type of filmmaker who is like, ‘I’m gonna hang out for two weeks with no camera.’ If I’m there, I’m filming.”

She opted to fill the movie with vérité footage instead of long sit-down interviews, using the onstage chats to reveal Obama’s backstory. Hallgren also decided against a formal question-and-answer session with Barack Obama, who only turns up briefly in the documentary after its first 30 minutes. Because the movie is from Michelle Obama’s perspective, the director decided to include her husband only when he naturally appeared in her life — like backstage after her D.C. tour stop, when she asks what he thought of the appearance.

Hallgren was also keen to convey Obama’s effect on strangers, which she first noticed during a book signing.

“I was really struck by how she locks into people when she meets them and is totally present,” she said. “She interacts a lot with young people and really enjoys the ability to share something of value with them — her wisdom and perspective, being able to talk through some of their fears about their futures. She’s just really good at it. She gets great joy out of doing it, and I think that might be why the advice is given with lots of love and thoughtfulness. From my observation, she gets as much joy from those interactions as the folks waiting on line do.”

One of the youths who crossed paths with Obama on tour was Shayla Allen, now a 17-year-old on the cusp of high school graduation in Philadelphia. During a surprise roundtable with Obama at her school, the onetime first lady offered Allen guidance on how to avoid being more than just a number in a world that focuses so much on GPA and test scores.

“Throughout my childhood, I’d been a dancer. And in competitions, you want to get to first place. You want to go to the best school in the city. You want to be valedictorian so you can choose the best college,” said Allen, who is planning to study biology at Arcadia University in the fall. “She told me to see myself as more than in a competition so I could realize all the things I loved and wanted to do with my life. It truly helped me to see I didn’t have to be a statistic to be good, as long as I’m myself.”

When Obama watched the first cut of “Becoming,” it was these interactions that she most enjoyed seeing on screen. Hallgren said she gave feedback about moments she loved — “like seeing people’s faces in the audience” — as well as guidance on how to strengthen the narrative.

“She knows her story better than me, no matter how many books I’ve read,” Hallgren said. “So she gave me tips to deepen her story, and it was really helpful.”

Ultimately, Hallgren hopes “Becoming” reinforces the importance of storytelling, and how transformative it can be to learn from another’s experience.

“Mrs. Obama’s mother would always say, ‘My kids aren’t special. There are millions of kids like them on the South Side of Chicago,’” the director said. “At a young age, Mrs. Obama was taught that it takes community and family and love to develop a level of confidence. She never felt invisible. When her guidance counselor said, ‘You’re not going to Princeton,’ she was wounded. But she had the inner confidence to say, ‘You’re not right about that.’”