David Hockney is doing wonderful work in old age. The film A Bigger Picture follows him around East Yorkshire as he gears up- at the rate of a canvas a day- for the huge- multi-canvas painting Bigger Trees Near Warter (which he was to show at the R.A. and then donate to the Tate). It's an odd thing about painters: while other types of artist slow down in their seventh decade, painters just go on getting brisker and better. Hockney attributes his unfaltering creativity to an extra large helping of the life force. Watching him is inspirational. It's rare for a major artist to be filmed at work. Pollock and Picasso allowed it. Hockney makes a third. I have little doubt he belongs in that company.