Sir Ian McKellen speaks of the 'special dwarf' with whom he forged a bond during The Hobbit

The actor, who plays Gandalf in The Hobbit: An Unexpected Journey, had to stand on a box in order to make the dwarf actors look smaller

Sir Ian McKellen's "favourite" part of filming The Hobbit was being surrounded by kneeling dwarves, according to Sir Peter Jackson.

The film's director explained how the dwarves were made to look smaller by having Sir Ian stand on a box, and added: "There's also Ian's favourite technique, which was the dwarves on their knees."

Sir Ian, who plays Gandalf in the film, said: "I adore all the dwarves, they know that. There is one special dwarf and he knows who he is, but enough of that."

The actor, 73, also spoke about the change involved in switching from playing Gandalf in The Lord Of The Rings trilogy to playing him again in The Hobbit.

"He comes back as the most boring man or wizard that could have possibly been invented," he said. "The beard is gone, he seems to have stopped having any fun and of course he has got to save Middle Earth so he's got a mission. He doesn't even have a pointy hat."

Philippa Boyens, who co-wrote the script, said she thought JRR Tolkien would have been pleased with the three-part adapted version of his novel.

She said: "Professor Tolkien said when he wrote this mythology he did hope it would have a life of its own. I can't imagine he would have huge issues with a lot of it. That wasn't his job to turn it into a film; that was our job."

Sir Peter, talking about the film's 3D technology, said there were no plans to create a 3D version of The Lord Of The Rings trilogy.

He added: "I'm so glad I don't have to go back and shoot The Lord Of The Rings again."

Speaking about the future of cinema, he said: "I really hate the idea that I am a director making a movie for an iPad. There is a degree of jeopardy for cinema now with all the ways people have to see movies now."

Martin Freeman, who stars as Bilbo, described his exhaustion from filming the second series of BBC's Sherlock in London and The Hobbit in New Zealand last year.

He said: "I didn't really get the chance to unwind. I spent 2011 being quite knackered. I handled it just by the glee of being able to do it really. I felt very lucky to be doing two jobs I really adored."

Talking about his hobbit feet, he added: "They were good for about a week. They were comfortable, then they were really uncomfortable."

PA