In 2009, after Chicago historian John Maloof published remarkable photos he'd bought at a storage facility's auction, mythology quickly developed about Vivian Maier, the unknown photographer. An extremely private woman who'd worked as a nanny for decades, Maier was eventually proven to be a considerable talent. In Finding Vivian Maier, Maloof and co-director Charlie Siskel unpeel the mystery around her; the contradictions they uncover and the questions that refuse to be answered make the film haunting and powerful despite its boilerplate documentary form -- captivating subjects talking to the camera; many shots of Maier's photos; newspaper clippings and home movie footage interspersed throughout. Because her tale is so fascinating, movie-making formula is all that's needed. Born in New York but speaking with an accent that passed for both French and German, Maier was something of a shape-shifter, described as alternately loving and abusive by men and women who were in her care as children. The tone darkens as the film digs deeper into her psyche, suggesting that despite the warmth in Maier's shots of ordinary people, she may have suffered a violent trauma (never named) that made her loathe men even as they proved some of her most sympathetically captured subjects. A trailblazer who found a way to turn her demanding job into a means of doing artistic work, Maier -- according to those who knew her -- would have despised this intrusion into her private life even as she'd have welcomed attention to her work. Her desire for both anonymity and creative expression is at odds with how the lust for celebrity and the creative impulse now seem synonymous. That's just one way she continues to seem wonderfully out of sync.