When you hear the word tear gas you think, well, your eyes will burn and that's it. But that whole feeling of your whole skin burning, that you can't breathe, you can't inhale, you feel suffocated - it's a very, very terrifying experience.

I think that the whole voyeuristic attitude of filmmakers or of me personally - of shooting documentaries and so forth - is an important issue. And it was an important issue to me, personally. And the whole question of when - when do you put the camera down or when do you keep shooting to get the shot. And a number of times in my life I've had that question hit me very hard.

The helicopter was a U.S. Navy helicopter. There were no civilian helicopters available to film companies, so they just made some stuff out of two-by-four wood. And I would straddle a two-by-four out from the helicopter with a camera and what we call a high hat, which is a low metal stand.

We, as film-makers, are privileged. We can make people cry or laugh. We can make them think and feel. It is a great privilege and a great responsibility.

Not one Wall Street executive has been charged with crimes since the 2008 financial crash.

Lighting was very primitive. And still it was really the way to learn because sometimes some of the modern technology is so extreme and so compartmentalized that we lose sight of exactly what we're doing.

When people have problems with their mortgages and jobs many feel they're a failure, they didn't work hard enough or speak well enough: It's their fault things are going so bad. When they see their bodies right there [at occupations], we have something profoundly in common.