Joe Stephenson has directed McKellen: Playing The Part, which is built around a 14-hour interview that explores McKellen?s life story.
Stephenson has said "He's a very gentle and quite a shy person. Which is quite a strange thing - a juxtaposition, really, with how outspoken he is about things and how brave he is and how much of a strong performer he is. He is actually quite a shy individual.
Joe claimed McKellen approaches many of his public appearances like a stage performance, meaning he doesn?t allow other people to get too close to him.
Stephenson was able to earn his trust so McKellen was happy to speak honestly about his life for the film.
Joe said: "I think if it was somebody he didn't know asking the questions that barrier would be up, and I don't think it would be really possible to penetrate.
'McKellen: Playing the Part' will be broadcast live to cinemas across the UK on May 27.