Robert Zemeckis on The Walk, Joe Wright on Pan

With Francine Stock.The director of The Walk and Back To The Future, Robert Zemeckis explains the rules of employing 3D in film, and why it shouldn't just be used for effect.Foley artist Barnaby Smyth demonstrates how he followed in the footsteps of Emmeline Pankhurst and co for the sound effects to Suffragette, which required him to wear specially adapted high heels.Joe Wright, the director of Pan explains why Nirvana's Smell Like Teen Spirit makes an unlikely appearance in his new adaptation of J.M. Barrie's classic children's tale.Denis Villeneuve reveals the pressure of making the sequel to Blade Runner.