Affleck's casting was initially met with resistance from the Caped Crusader fans. The actor, however, revealed that he himself was a huge fan of the superhero.
"It's certainly daunting because of the people who have played this character before and the great filmmakers," he said.
"Most recently Christian (Bale) and Chris (Nolan) who made brilliant movies. There is that element of healthy respect you have for the project and for the characters and their history."
"I think I tapped into equal measure of my adult geekness and kid excitement. Every day there was something to kind of geek out about. It was exciting every day."
Affleck believes the audience gets drawn to the character because despite his powers, he is a vulnerable personality.
"Batman is a guy who on the one hand is powerful and exciting and can do things we all wish we could do but is also still a human being and struggling with his own vulnerabilities," he said.