Stephen Sackur speaks to Steve McQueen, the Oscar-winning director of films including 12 Years a Slave and Widows. Much of his work has portrayed racial injustice, and his latest film, Blitz, tells the story of a black boy caught up in war-torn London in 1940. His images are often difficult to bear - how important is it not to look away? Image: Steve McQueen (Credit: Andy Rain/EPA-EFE/REX/Shutterstock)