Director Nolan: Superman movie harder than Batman

Christopher Nolan has revealed making a Superman movie is harder than bringing Batman to life on the big screen.

The director - who helmed the 'Dark Knight' trilogy starring Christian Bale - serves as a producer on Superman reboot 'Man of Steel', directed by Zack Snyder, and admits it's been a much tougher process to make because of the complex mythology and super-human powers the iconic Krypton-born superhero has.