The long life of German photographer August Sander (1876-1964) spanned one of the most turbulent eras in his country's history. The Great War of 1914-1918, the Weimar Republic, the reign of National Socialism, and the horrors of World War II all left an indelible imprint on both the man and his work. Sander, a conventional studio portraitist who transformed himself into an avant-gardist, exemplified the complex and sometimes contradictory nature of...