Thomas von Steinaecker’s documentary portrait of Werner Herzog, the singular German film-making talent who gave us pictures such as Aguirre, Wrath of God, Fitzcarraldo and the documentary Grizzly Man, is every bit as fascinating as you would hope. A director who is not just open to the chaos on the fringes of civilisation, but who voluntarily invites it into his life (in the form of the actor and world-class pain in the ass Klaus Kinski), Herzog has a wealth of meaty anecdotes. Radical Dreamer is less successful in its attempt to bring in other voices to appraise his legacy: interviewees tie themselves in knots of gushing superlatives, but the real insights come from the man himself.