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.

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 a photographer cares about the people before the lens and is compassionate, much is given. It is the photographer, not the camera, that is the instrument.

What I have tried to do is involve the people I was photographing... if they were willing to give, I was willing to photograph.

If the chemistry is right between star and photographer and the geometry of the pictures pleases the star, often the two people end up with a long-term professional friendship during which they continue to work together and to produce highly personal images.

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

Recording sessions were stimulating to photograph, because everything was in motion: the subject, the musicians, the technicians and the photographer. You needed fast reflexes to keep up with moving targets, and sensitivity and skill to get the pictures while keeping out of the performers' eyeline so as not to break their concentration.