Roger Ballen's photographs journey from the disturbing documentary images of his early series in rural South Africa to the disturbed interiors of his recent compositions, taken around Johannesburg. It started with a journey, with the young American hitting the hippie highway in 1973 and travelling overland from Cairo to Cape Town.

"I stayed awhile, then went on another journey from Istanbul to New Guinea before going back to America in 1977," says Ballen.

His first book, Boyhood, was drawn from pictures taken during those travels, but his name was made by the work he did after returning to his wife's country of South Africa in the early 1980s, which is included in the retrospective at AUT University's St Paul St Gallery.

Ballen has been seeing the world through a lens since he was a small boy. "My mother started one of the first photography galleries in New York in the 1960s, and I got seriously interested. I knew the leading photographers of the time."

That interest gave him a comprehensive understanding of the craft, but it didn't extend to wanting to become a commercial photographer or a photojournalist - the options for a photographer in the era before photography was considered a proper art.

Instead he secured a PhD in geology and mineral exploration, and continued to take pictures as a hobby. Prospecting in the back blocks of South Africa, Ballen would shelter from the heat of the day by knocking on people's doors.

From those encounters came the images in his first important collection, Dorps, Small Towns of South Africa. The following book, Platteland, extended the ideas and created sufficient impact for Ballen to seek interest outside the country.

"My early pictures were more documentary in terms of the questions I was asking, and the images were more about the culture I was in. For the Dorps project the question was, 'What is the unique aesthetic sensibility of these small towns?'.

"In Platteland, the pictures of poor white South Africans on the margins were a metaphor for emotional states."

By the mid-90s, when he settled in Johannesburg and pursued photography fulltime, the work was becoming increasingly complex and metaphorical. The next collection, Outland, took a more theatrical approach, with its subjects performing in mysterious tableaux.

"They would add something, I would add something. I was asking questions like how would people deal with their ultimate fear, how would they deal with shadows."

That exploration of metaphor continued in later collections like Fact of Fiction, Shadow Chamber, and the most recent, Boarding House, in which fragmentary human or animal subjects compete with drawn and stained walls, worn out furniture, grime and mysterious sculptures.

"When I was working in those small towns, when I went into buildings I started to pick up on little visual aspects, the wires on a wall, the objects that were round. Seeing the world round these places expanded to a way of seeing. You can look at the formal qualities of that work and how it developed over the years to end up as Boarding House."

Ballen says to try and read his work against the political upheavals of South Africa over the past two decades was to misread it. "I am not a political photographer. What I do is existential and psychological. I am looking to find a more universal sensibility."

While pictures can speak about people and place, they also need to find a place in the mind of the viewer.

"For a picture to last as an artwork, it has to go beyond the particular circumstance of its creation, it has to go beyond time. If you look at these photos, you do not need to know about what happened here. You can look and find things in your own being that somehow ask questions about yourself or the way you live or the world you live in.

"In everything we do we are part of a culture, we are part of our time, we can never escape that, but it's important for me to go past place and time and create timelessness in the images. If you think of the millions of pictures taken in World War II, which ones last and why? Certain things last because they document a certain period or place, but others last because they say something deeper about the human psyche."

Ballen says there were advantages in working in isolated places like South Africa and New Zealand.

"There was no one to lean on, no work to look at. It was up to me to find a vision and a path. In Paris or New York, there would be a thousand other people doing exactly the same thing. I'm not following trends. I'm not interested in what's going on in the contemporary art world . Ultimately, I have no control over that. I have been driven purely by my own existential needs."

In response to an email query about the background of two of Ballen's images, he writes: "The photograph of the twins was taken in Western Transvaal in 1993. While I was driving around the village they lived in, I noticed one of the twins was gardening in the front garden. His presence struck me enough to stop and start talking to him. After some time, he agreed to be photographed and I placed him against a wall on the verandah of his house.

"As I was taking his photograph I noticed a shadow coming from behind me. As I turned my head, to my great surprise, there was his twin brother, Casie. Casie's shirt was very clean as he spent his day inside cleaning the house while his brother Dresie's shirt was dirty as he spent his day gardening.

"In Twirling Wires, the man was staying in a farm house where there were balls of barbed wire. I photographed this person within 20 minutes of meeting him. Sometime afterwards, he was found dead in the same place, having been dead for three weeks already."

Who: Photographer Roger Ballen
Where and when: St Paul St Gallery, 40 St Paul St, to May 29