"Claude Lanzmann: Spectres of the Shoah" begins by putting the eponymous journalist/filmmaker's monumental nine-and-a-half-hour documentary on the Holocaust, Shoah (1985), in a quick context with thoughts from the likes of film critic Richard Brody and director Marcel Ophuls. It then dives headlong into a study of its making, with Lanzmann recounting the great emotional toll the seven years of production and five years of editing had on him. It is at once a fascinating portrait of a man openly pessimistic about the world, and a unique distillation of a creative process that yielded one of the most powerful cinematic documents of our time.