From New Zealand to Turkey to Oxfordshire this artist captures light in its transience and radiance especially with his paintings of water in all its different manifestations. Take Brien O'Rourke's two pictures of the beach at Steward Island, New Zealand, Ulva 1 and 2, with their sense of isolation, or the Path up to Rob Roy Glacier with its frighteningly steep incline - one feels one might be washed away. And there is the threatening and darkly grey Tolkien country of Greymouth on the West Coast of South Island. All are beautifully framed by O'Rourke himself.

He sold his first painting when he was 17 and has worked as an illustrator and teacher. Sometimes accused of having too many different styles, it is rather how he handles his paint to suit his subject matter that is unique. He can layer thick, textured slabs with a knife or use light brush work, as in Cap Blanc, with the lighthouse perched high on the chalky hill overlooking a pale sea in this altogether more gentle, Victorian-like picture.

In a different mood the light changes from moment to moment over the dull landscape of Faringdon Field, while in the small, deep Mediterranean blue painting of a sun-filled Steward Island the towering tree trunks are silhouetted in the foreground.

A formidable part of the exhibition is the series on "The Green Man", the archetypal ritualistic and elemental figure based on folklore and fairy tales. It coincides with research being done by Tim Healey on both the Green Man in Oxfordshire and the cult film The Wicker Man, now remade and on general release. In O'Rourke's compelling paintings he includes abstract symbols of fertility and reproduction, as in Winter whose soggy liquidity suggests a foetus in the womb, and from Botticelli's Birth of Venus he transposes vegetal forms and idea of the green woman. The glory of these later pictures is manifest in the many shades of green from vivid emerald to lime and jade.