Cecil Beaton is one of those odd birds in 20th-century cultural lore, virtually a household name. but many would be hard-pressed to say for what. Director Lisa Immordino Vreeland’s documentary does a smashing job of filling in the blanks and chronology of this restless, multitalented Brit. He was a legendary and enormously artistic photographer to the rich, famous, and royal — from Hollywood (Dietrich, Garbo, Orson Welles) to Buckingham Palace to the art and music scene (Warhol, Jagger) — and captured Blitzkrieg-torn London (some of those images recently showed at SBMA). Beaton (1904-1980) was also a fashion illustrator and staff photographer for Vogue, a diarist, bon vivant, self-absorbed dandy, and fascinating enigma. A self-admitted “terrible homosexualist” when that was illegal in England, Beaton came from modest means but groomed himself for social climbing; he was drawn to theater, visual arts, and writing. Yet his truest mastery was photography. One of the film’s seductive charms is Vreeland’s uncommonly fluid way of capturing the essence of his powerful photography in cinematic terms. Come for the story, but stay for the pictures.