Ian McKellen broke down over 'Hobbit' green screen scenes

Actor snapped filming scenes without other actors due to size difference of his character with dwarves

Sir Ian McKellen has said that he cried with frustration over filming scenes for Peter Jackson's new 'Hobbit' film with a green screen instead of with other actors.

The actor, who has played Gandalf since Jackson's first 'Lord of the Rings' film, became upset after he had to perform the scenes with only pictures of his other cast-mates.

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Gandalf... McKellen got sick of acting without other actors (Copyright: Warner Bros)

“In order to shoot the dwarves and a large Gandalf, we couldn't be in the same set. All I had for company was 13 photographs of the dwarves on top of stands with little lights - whoever's talking flashes up,” he told Contact Music.

“Pretending you're with 13 other people when you're on your own, it stretches your technical ability to the absolute limits.

“I cried, actually. I cried. Then I said out loud, 'This is not why I became an actor'. Unfortunately the microphone was on and the whole studio heard.”

McKellen is currently on the publicity tour for 'The Hobbit: An Unexpected Journey', the first in three films to be made from Tolkien's book.

It's due out in the UK on December 13.