The reason why so many of my photographs in the book were taken in stairwells and corridors was that that was the only bit of spare space available and, in some cases, the only place where there was enough light to see anything. Even then, it was often so dark that I couldn't tell which gender my subject was (not that I particularly cared) and too dark, before the era of autofocus, to focus. I had to find a light (or carry a torch) and pre-focus.

That's one of the wonderful things about the whole process of photography - eye contact can be very revealing.

Things are very different now because a lot of those little clubs don't exist. In Soho for instance, where nearly half my nightlife photographs were taken, it's rapidly changing. There isn't the same after dark frisson of excitement about the place any more.

When I gave up my office job and became a full-time professional photographer, my fortunes certainly improved markedly. We moved away from the council estate into our own house and for the first time in my life, I had a little spare money.

I preferred that option, where my camera (and by proxy, me) could look them straight in the eye. The way they reacted to me was always interesting. Sometimes hard young men would reveal vulnerability and a softer side. In the case of teenage girls, I often got a fascinating glimpse of the woman inside.

When I was starting, I was very much influenced by the straight up, eyes to camera style of August Sander. He is really the only one. Had I known then the work of people like Ken Russell, Vivian Maier, Helen Levitt, and Steven Berkoff, they would undoubtedly have influenced me too.

My parents, though very loving, were not what one would ever describe as outgoing and therefore when I was young I was quite shy and socially awkward. Having a camera changed all that. It gave me an excuse to go anywhere and approach anybody.