More than 100,000 negatives shot by Maier depicting New York street life were brought to public attention after being sold off when Maier fell behind on payments for the storage locker in which they were kept.

Some of the images were discovered by Jonathan Maloof, who subsequently became a champion promoter of Maier’s photographic street photography and is now at the core of a project to reconstruct her archive.

Maloof is also one of the directors of the documentary, along with Charlie Siskel.

Maier began taking photographs in 1949 on a Kodak Box Brownie, and continued up until her death in 2009. Throughout her entire life she kept the photographs secret, and relatively few people knew she even practised photography as a hobby.

Watch the trailer for the film below:

More information is available at the film’s official website and Facebook page. The film will debut on July 18 in London’s Covent Garden.