Tomas Alfredson: 'I was bought up on film sets; my own kids think they're boring'

As a child, film meant the possibility of being closer to my father He had been making films since before I was born, so I was brought up on different film sets and I learnt a lot about the process that has been useful to me as a director. But at the time it was mainly something I knew I could talk to him about.

I try to keep my own kids away from my sets It's easy, as they think they're boring. A film set is a place where grown-ups play – and shooting has to be playful, as it must feel as though it's the first time something has happened – but I don't think it's good for kids to be there. They ought to be in real playgrounds.

I look for the things that make us alike rather than different I don't know how it was to be a British spy in 1973, as in [Alfredson's Bafta-nominated latest film] Tinker Tailor Soldier Spy, or indeed what it's like to be a vampire, as in [his breakthrough 2008 film] Let the Right One In. Everything feels foreign when you start to make a film, but you try to fill in the gaps.

Atmosphere in film is about making images out of a feeling Sometimes it is just a certain light or a texture of a surface, or even a melody. You might listen to a song on the radio and you know that is how you want a scene to feel – then you have to sit down and work out how to do that visually.

It's not for me to decide how people consume my work It's sad to think that your films are watched on crappy mobile-phone screens with kids shouting in the background rather than in a cinema, but as a director there is nothing you can do about that.

The most fantastic thing about film-making is that you imagine something and then two years later you see your imagination exactly materialised in celluloid. Sometimes the eventual result is not quite the same as you had originally visualised, because you collaborate with so many people, but that tends to mean it is something better.

The best film-maker that has ever been is Hergé, the creator of The Adventures of Tintin. For me, his storyboards constitute cinema.

Tomas Alfredson, 46, is a Swedish director. 'Tinker Tailor Soldier Spy' is out on DVD now. It is nominated for 11 Baftas tonight