SAN JOSE, CA.- David Hockney: Bigger Picture is film-maker Bruno Wollheim’s account of David Hockney’s return to his native Yorkshire, after 25 years of living in California. Filmed over three years, it finds the artist at a crisis point in his life and art. Hockney has come back to oil painting after a six-year break, for the first time working outside, directly from nature, en plein air. At the age of 70, he is painting through the seasons and in all weathers. He also wants to be filmed at work – another first.

It emerges that Hockney wants to co-opt the documentary on an anti-photographic mission to prove the superiority of painting as visual truth. His recent work on the controversial book and film Secret Knowledge has convinced him that Western art for the last 500 years has embraced a photographic view of the world, and that he must abandon the camera, up to then the mainstay of his art. The film traces Hockney’s uneasy love affair with photography and pursues a dialogue between the two media.

Step by step, the film records Hockney’s efforts to re-learn his craft from first principles: going back to the natural world for inspiration, using watercolour for a greater directness, the study of ancient Chinese Scrolls, the rapid strides he makes with oils in both technique and ambition.

Interviews with Hockney and his sister Margaret reveal more personal motives for his homecoming. His dachshunds have died, so have many of his friends. The death-bed wish of a close Yorkshire friend also plays a part, so too his mother’s death which frees up the house in the remote seaside resort of Bridlington where she’d spent her last years. He’s also back in the fields where as a schoolboy he took holiday jobs.

Hockney rediscovers the spectacle of England’s rapidly changing seasons, finding renewal and connection. His prolonged contact with Nature’s life-force brings an increasing abstraction to his art and a growing sense of his own mortality and isolation. A complex portrait emerges of an artist as an older man whose art can stop time running out.

The film culminates in the largest painting ever made outdoors, created in three weeks for The Royal Academy’s Summer Show. Hockney is making a statement about painting, pitting himself against the new YBA status quo - to which Damien Hirst provides a droll riposte. When he gives the picture to the Nation, the question of legacy hangs in the air.

In a final twist, Hockney starts working with digital photography. When challenged, he quotes another artist “only believe what an artist does, not what they say!”, a reminder that truth and artistic licence go hand-in-hand. Hockney remains elusive, equally on the topic of his homecoming. As he takes a wintry sunset drive along familiar country lanes, he quotes Van Gogh “I lost the faith of my father but found another in the infinity of Nature”.