The Genius of Photography
This six-part BBC documentary, The Genius of Photography, is thoroughly excellent and all viewable for free on YouTube; double excellence. (Edit: No longer true.)
One of the many highlights is an interview with Colin Wood, the subject of Diane Arbus’ Child With Toy Hand Grenade in Central Park, 40 some-odd years later. Wood reflects on the person he was back then and speculates on what Arbus may have seen in him.