By their very nature, photographs are loaded with backstory. There's the image itself, deemed important in a moment that becomes frozen for eternity.
And there's the person who snapped the picture, for reasons that are as personal as they are mysterious.
In the fascinating new documentary Finding Vivian Maier, the title character's exceptional photographs are brought to light after years of being hidden away from any and all scrutiny.
John Maloof (the film's co-director with Charlie Siskel) discovered Vivian Maier's work by chance.
He was working on a book about the history of his northwest Chicago neighborhood and looking for vintage photos at an auction.
A box of negatives he purchased for $400 were shelved for some time (they didn't even make it into the book) but something about the pictures nagged at him.
After consulting with other photographers, he realized the pictures were taken by an unknown, Vivian Maier, and had a distinct aesthetic; there was a stark artistry and dark genius about them he and others couldn't dismiss. He threw out a plea for more of Maier's shadowy portfolio and ended up with over 100,000 negatives, 3,000 prints, and hundreds of rolls of undeveloped film.
Shot largely in crisp black-and-white, in commercial and public urban settings, the images vibrated with the cacophonous pulse of those parts of city life many eyes turn away from.
Though possessed of an unmistakable point of view, they reminded experts of more famous photographers; some had the grit and gristle of the photojournalist known as Weegee while others captured the random beauty of the grotesque so prevalent in the work of Diane Arbus.
A strange and intoxicating piece of the puzzle was the fact that Vivian Maier herself shows up in many of her photographs, reflected in store windows or hotel mirrors, with her big, boxy camera hung around her neck and resting near her pelvis.
The filmmakers' hunger for more information about who Maier was drives the second half of the movie, where we learn she was born in Europe, became a nanny for rich American families for most of her life, and spent her last years encaged by the results of hoarding.
Several of her now grown-up charges wax nostalgic about accompanying her and her camera while also acknowledging she could be vicious. And almost to a person, they agree they never really knew her.
There can only be speculation about why Maier's photographs never surfaced. But there's an abundance of evidence that she ranks among the greatest unsung artists of the twentieth century.