For nearly 40 years Roger Ballen has been an outsider, operating on the margins with his fellow art brut artists. Now a new book and exhibition offer a glimpse inside the workings and processes of his dark mind, a world, he says, that, 'reveals itself through itself'

You were born in New York and later moved to and lived in South Africa for many years, you have shot a great deal of images of white people who live in South Africa, what is your original creative thought? How does this migration, geo-cultural difference influence your creation? Roger Ballen: I really took a lot of pictures of African white...