Gemma Arterton doesn't think she's a good movie actress.

The 'Quantum of Solace' star thinks her classically trained background and theatre experience have gone against her when it comes to film roles and she finds it hard to adapt her performance when she's on set shooting Hollywood blockbusters.

She told The Times newspaper: ''I haven't learnt how to moderate my performance for the camera. On film I often feel that because I can't see the audience - because they're in the camera - I haven't learnt how to judge that. I fell like I'm a much better theatre actress than a screen actress.''

The 27-year-old beauty stars alongside veteran acting legend Terence Stamp in her new British drama 'Song For Marion', and while she was nervous about acting opposite the notoriously stern star, she warmed to him quickly.

Gemma admitted her first thought was: ''I'm not going to get on with him. He's stiff. He's odd.''

However, watching Terence's stellar performance in the film, particularly when he stands alone and sings a tear-jerking a cappella version of Billy Joel's 'Lullabye', melted Gemma's heart.

She explained: ''We were all sitting there watching him do it, and everyone was crying. And it's amazing to be on the set when that's happening. You feel, 'Ooooh, this is a bit of magic.' ''