"I haven't done it by myself at all. I've been surrounded by a really, really good crew of all ages. I think it's important to have a good age range in the crew so that some of us have experienced that period, or something close to that. But the script, of course, is really inspiring and you just have to trust that. Sometimes on film a glass can be as big as a car, so if the details are right, then they take up as much space on screen as the streets that we didn't have a chance to show as London really has changed since then."