Included on the Criterion Collection edition of Kirsten Johnson’s documentary “Cameraperson” is a 2015 short film she made from her time in Afghanistan, “The Above.” The documentary profiles not a person but a thing — a whale-sized surveillance balloon that the U.S. military put into the air over Kabul for reasons that remain classified.

In shot after shot, we see Afghan residents going about their daily lives, all with this big white blimp hanging in the background, watching. The balloon is meant to be inobtrusive, but once you notice it, you can’t unnotice it, and knowing it’s there over your shoulder must color everything done by the watched. It could be the eye of God — or the lens of a cameraperson.

Johnson was likely thinking of herself when she made “The Above.” A celebrated cinematographer who has traveled the globe making documentaries, “Cameraperson” is a collage of unused footage that she calls “images that have marked me.” Ranging from a close call with authorities outside a “black box site” in Yemen to an explosive boxer in New York, from two women happily chopping down a tree in Darfur to footage of Johnson’s own Alzheimer’s-afflicted mother, what seems like a random assemblage crystallizes into a finely-constructed mosaic of the human condition.

Beauty and ugliness, kindness and cruelty, anger and peace, it all exists side by side, and sometimes inside each other. Returning to Bosnia years later after making a documentary about mass rapes committed there, Johnson confesses to the family she filmed that what stayed with her isn’t the atrocities, but the beautiful landscape and the warmth of the people.

And that’s the key to “Cameraperson.” In few other documentaries have we ever been so aware of the person behind the camera, choosing what to show us and what to leave out. Sometimes these choices are explicit – we see Johnson setting up a shot, getting just the right angle, composing within the frame.

But, more importantly, it’s about what Johnson chooses to film and not to film, to see and not see, whether the camera follows the nurse as she hustles out the room for help or holds on that newborn baby, gasping for life. Woven together with Johnson’s own life, her mother at the end of her life and her children at the beginning of theirs, this is autobiography in its truest form, a visual document of choices made and chances taken, and missed.

It’s important to watch “Cameraperson” the first time through without context, to let those images work together on their own. But the bonus features on the Criterion edition are invaluable in showing how Johnston and her team put the film together.

In one behind-the-scenes feature, Johnson talks about how an initial version of the film was dubbed “The Trauma Cut,” because it seemed to focus on everything that was too awful to put into the documentaries that Johnson was shooting at the time. Editor Nels Bangerter went through the footage again, this time looking for moments when Johnson’s presence could be felt through the footage she’s shooting, whether it’s a shadow on the ground, a friendly interaction with an old man she’s shooting, even a sneeze that jiggles the camera. The result makes for the personal film we see.

The second bonus feature is even better, an invaluable roundtable between Johnson, sound engineers Wellington Bowler and Judy Karp, and producer Gini Reticker about what it’s actually like out in the field shooting these kinds of things. Bowler explains how the sound engineer and cameraperson work in tandem — while the camera operator is focused on what’s in the lens, the sound engineer has to be alive and aware to everything that’s going on around them, 360 degrees. That means it’s often the sound engineer who picks up on when things in a country like Liberia or Darfur have grown too dangerous to film — a crew will have a shorthand “Time to go!” gesture they share that instantly alerts them to shut down filming and leave a scene.

Even more interesting is when the documentary filmmakers talk about their relationship with the people they are filming, often people at the lowest point of their lives. They agree that they’re not just going to parachute in and “get the shot,” but need to spend time with these people, connect with them. But they also recognize that, if they do bond with their subjects, it’s better for the film.

It’s fascinating stuff for fans of documentaries. “Cameraperson” was one of my favorite documentaries of 2016, and the new Criterion election illuminates all the thought and care that went into that indelible footage. It also screens March 10 at 6 p.m. at the Union South Marquee Theatre as part of the new Directress Film Festival honoring women filmmakers.