I have been poor and I wanted to document poverty; I had lost a child and I was obsessed with birth; I was interested in politics and I wanted to know how it affected our lives; I am a woman and I wanted to know about women.

Lesson number one: Pay attention to the intrusion of the camera.

I found a way of working which pleased me because I didn’t have to frighten people with heavy equipment. It was that little black box and me.

What has changed is that when I photographed, most people that I photographed didn't have the right of refusal on their work. It would take a Marilyn Monroe at her height to be able to dictate that.

I realise that I had the best of serious picture journalism. There was an innocence in our approach, especially in the 1950s and 1960s when we naively believed that by holding a mirror up to the world we could help - no matter how little - to make people aware of the human condition.

If you are careful with people, they will offer you part of themselves. That is the big secret.

I look for a sense of reality with everything I did. I didn't work in a studio, I didn't light anything. I found a way of working which pleased me because I didn't have to frighten people with heavy equipment. It was that little black box and me and £5 worth of film in my pocket or maybe it was only £2 in those days.