There are a ton of things a photographer has to do to make a great image: Get the perfect light, find a killer composition, focus — but for former White House photographer Amanda Lucidon, the most important one was just showing up.

In a new book, “Chasing Light,” Lucidon, whose primary job was to chronicle first lady Michelle Obama, said she lived in fear of arriving too late, getting left behind and being unable to do her job, which she describes as “documenting the presidency for history.” To make sure her nightmare didn’t come true, she writes, she adopted a mantra: “The motorcade only waits for one person … and it’s not you.”

Lucidon doesn’t seem to have gotten left behind; the book is packed with images of Michelle Obama in public and private moments — with her husband, her daughters, schoolchildren, visiting dignitaries and celebrities, in settings from the Great Wall of China to the White House kitchen garden.

In the book, the former freelance photographer also offers some insider recollections. For instance, she writes about how one of the best-known images of the Obamas’ White House years — a candid photo of Michelle Obama grinning like a schoolgirl with her crush as she snuggles next to the president while he leans toward her — almost didn’t happen.  The picture was taken when the couple was filming a taped video segment, Lucidon remembers, and she had time only for a single snap. “It happened so quickly that I didn’t have time to compose the image,” she says.

She also describes the admiration she developed for her subject, who became a mentor and role model. “She has always been a shining example of the light I was chasing in my own life,” she writes. “Watching her through the lens of my camera, I learned so much about myself and life I wanted to create.”

In an interview Monday, Lucidon said her book tour has put her in a spot she’s not used to: in front of the cameras. “I think I prefer being behind them,” she said. But since she’s the subject now, we finally got to ask the question that’s been burning since we flipped through 200-plus pages of Michelle Obama looking flawless: Did the first lady ever really hate a picture of herself? Did the woman ever have a bad hair day?

Lucidon laughed. “As White House photographers, we were in a very trusted role,” she said. “There was never a time when we were told not to take a photo.”

We got even more behind the scenes with her as she described the sheer logistics of the job. “I’m 5’4″ and the first lady is much taller, so even when she’s walking, I’m running,” she said. Another challenge was staying ahead of the first lady as she arrived at various places (“I was always hopping out of the motorcade and running”) to capture people’s reactions to encountering the first lady.

One such photo happens to be one of Lucidon’s favorites from her years at the White House. It’s Michelle Obama, seen from behind, surprising a group of students by dropping by their tour. Some are clapping, some are crying, and others are cracking up. “It’s just raw emotion,” she says. “And that encapsulates a lot of what I was able to witness.”

Lucidon isn’t the only Obama-era photographer stepping out from behind the lens to share her own story. Pete Souza, the chief White House photographer who has developed a large social media following for his pointed posts contrasting Obama with President Trump, has a book coming out next month.