Acclaimed filmmaker Ken Burns, renowned for his documentaries on such topics as the Civil War, baseball, jazz and the Statue of Liberty, has now focused on 15th century Italian artist and intellectual Leonardo da Vinci. Correspondent David Pogue talks with Burns and his producing partners, daughter Sarah Burns and son-in-law David McMahon, about their PBS documentary on the man Burns calls "one of the most incredibly interesting human beings who has ever walked the Earth."