The winning portrait, Five Girls, was plucked from his Teenage Pre-occupation series; a beautiful body of work that explores youth in all its wonderful confusion and glory.
Stewart said: “Being surrounded by teenagers (my sons, daughter and their friends) made me aware of some interesting things about them which may be of the time and current culture. The work is a document of teenage preoccupations at this time. The world is changing around us very fast at the moment and it is a good time to photograph it.
"The subjects are insecure, looking for something to follow or not, to fit in or not, weighed down by technology, anti-social networkers, obsessed with what other people are doing. When photographed, all these things become clearer. I am presenting observations from the outside. The teenagers in the pictures think they are just getting on with their normal lives."