Garry Winogrand was looking for answers. Unlike most of us, he looked for his through the viewfinder of a 35mm Leica, snapping the 1960 Democratic National Convention, hippie "be-ins," and random people on the street, seeking the heart of America and the humanity behind the spin. His photos of the 1960s show a country tumbled by politics, angled skyscrapers, the Apollo moon landing, and gender and race roles reinforced by tradition and fashion. But most of all, they show faces: closed in suspicion or turned away to gossip, caught shocked and bored and defiant. In the 1980s, Winogrand told PBS, "All a photograph ever does is describe light on surface; that's all there is. And that's all we really know about anybody: what we see." But his photos somehow revealed something deeper about the world than its surface features. Maybe it's just because he was selective about what he showed us. He shot compulsively, and chose judiciously. When he died of cancer at the age of 56 in 1984, he left more than 2,500 undeveloped rolls of film. That's a lot of light on surface. That this show opens on September 11 adds just a little more chiaroscuro to Winogrand's shading.