"I've seen many sad things. I'm compassionate. I can't separate myself from people I photograph. In Rwanda, I talked to children who had seen their parents hacked to death. I couldn't go on. I said never to touch a camera again.
"Then I saw a beautiful yellow butterfly land on a sunflower and ran for my camera. Somehow this image brought me back. I had to retire from the UN. Now my mission is to capture images of hope."
A 1978 Photokina gold medal catapulted John into a UN career, documenting conflicts and disasters in 100 countries, and winning Time and Graphis awards. Eventually, he became the UN's chief photographer.
Today John's photographic life includes stellar wildlife and travel images, a book on Kashmir and a major retrospective exhibition.