Lots of crime films are about work. Free Fire could have been about a company of plumbers doing pipe-fixing and stuff. But the plumbing film is not so exciting.

I think CGI is interesting but it's too expensive and limiting in terms of what you can do shot-by-shot.

If you make a movie in the UK you've got to embrace the weather with open arms... We got some of the most amazing weather as well. It's maybe why some of these places, like the Lake District, don't get filmed in so much. If you were trying to make it look like some kind of chocolate box image of England you'd be there all year waiting for the sun to come out.

People say, "How do you get into the British film industry?" There is no British film industry, there are just people making films and finding their own way. It's not like in the States where there are studios and there's an actual infrastructure to it; there's just nothing here. You make it from scratch a lot of the time.

I'm very superstitious about going on other people's sets. You have to ask permission of the director; you shouldn't just turn up and skulk about in the background. It's very rude. You have to ask them personally. It's like a vampire being invited into a house.

The things that inspire people to think are what keeps a film alive.

I tend to shoot really quick so you don't get the problems you might get on a traditional film where you shoot one way, then another, and it's pissing down with rain and they won't cut together. We shoot so fast we can incorporate the weather into it. The worst weather we had was when they were in the caravan up the mountain and there was no cover. One man's weather is another man's production value. To create the sleet would cost a fortune but we got it for free so we'll just have to go with it.