It is a moment of great intimacy, a perspective experienced by very few.

While Lucian Freud is lost in concentration, his sitter turns the tables on the artist.

Using a snapshot camera, the model captured this very personal portrait of one of Britain's greatest living artists at work.

David Dawson spent a year sitting for Freud, 83, at his studio in Holland Park.

In contrast, Mr Dawson took just a few seconds to compose his photograph.

Shown together for the first time here, they provide a fascinating glimpse of the intense atmosphere of creation.

Mr Dawson, 46, himself an artist who has been Freud's studio-assistant for 15 years, said: "I don't think Lucian was aware of the camera at that moment.

"He really is concentrating when he is painting and I did it very quickly. I just had the camera down the side of the chair.

"I didn't do it in a subversive way. I thought, 'Wow, this is a really good moment.' I was interested in the atmosphere. This is what it's like when Lucian is really concentrating. It's not always completely quiet. I also have conversations and Lucian recites verse or sings. It can be high-spirited."

The painting, Eli and David, has been sold.

. Freud at Work: Photographs by Bruce Bernard and David Dawson, is at Hazlitt Holland-Hibbert, 38 Bury Street SW1, from Wednesday to 3 November.