I am riveted by extreme sports like big-wave surfing, 'megaramp' skateboarding and half pipe snowboarding. I am fascinated partly because the sports are so exhilaratingly acrobatic. But I am also captivated by the fear that a terrible accident might happen at any moment. And accidents do happen.

I am riveted by extreme sports like big-wave surfing, 'megaramp' skateboarding and half pipe snowboarding. I am fascinated partly because the sports are so exhilaratingly acrobatic. But I am also captivated by the fear that a terrible accident might happen at any moment. And accidents do happen.

With portable cameras and affordable data and non-linear digital editing, I think this is a golden age of documentary filmmaking. These new technologies mean we can make complicated, beautifully crafted and cinematic films about real-life stories.

I can ask someone to let me into all aspects of their life for several years, but people have got to have that gift: that courage and that talent for opening their lives to the camera. Being candid is a gift, and that's what the audience responds to. Part of it is me asking, and part of it is just their inherent talent, which is what you are looking for when you make documentaries - people that are really going to let you in on what they are going through.

Extreme sports tricks are becoming increasingly complex, the courses ever more challenging and crashes all too common.

I love my work, apart from when it's driving me crazy. But I get to be interested in stuff and think like a filmmaker as I'm buzzing about the world and then see an opportunity to make a film, and then make it happen.

I don't believe in objectivity. I observe the observer's paradox every moment I'm filming. Your presence is changing everything; there's no mistaking it. And you have a responsibility.