Hardly anyone knew Diana. Yet on her death the world mourned. They did not mourn the woman but her photographic image. We all think we know David Beckham; thousands of fans have seen him in the flesh on the pitch, but millions of us know him only through his image. The same goes for all celebrities, whether it's Madonna, Prince William or Tony Blair. The result is that the photograph becomes more real than the actual person or event. In my work I use celebrity lookalikes to create images which pose fundamental questions about where the truth ends and the the lies begin. The line between what is real and what is fantasy has never been more blurred. My photographs seek to explore the gap between the two and, if only for a second, bring it sharply into focus. Alison Jackson