German painter Gerhard Richter feels at times like half-a-dozen artists rolled into one.

In his figurative work, he ranges from near-photorealism to a kind of "distortionism" in which photograph-based images loom as if from under layers of rain-streaked glass. In his abstract work, obsessive neatness (tidy color-chart checkerboards, for instance) alternates with fluid smears and curls of color.

And then there's the variety of that color: from the brashest yellows to the gloomiest grays.

In her documentary, "Gerhard Richter Painting," Corinna Belz delivers exactly what her title promises: the sight of Richter at work on his canvases.

Richter fans wanting to observe how he creates his exquisitely controlled manipulations of figurative imagery will be disappointed. While we glimpse a number of those masterpieces at a retrospective at London's National Portrait Gallery, we don't catch sight of them as works in progress.

There's probably a good reason for that. They must be painstakingly slow in the creation, while Richter's abstract work — at least when he's starting on a new canvas — couldn't be more swift or spontaneous.

Wielding large paintbrushes, larger squeegee/scrapers and even the odd carving knife, Richter puts his canvases through a protean dance. They change from session to session so rapidly and drastically that Belz's film sometimes seems an accidental work of animation.

Small snippets of Richter's biography and clips from archival interviews pepper the film, with Richter growing most somber when he's asked whether, when he fled from East Germany to the West in 1961, he knew it would mean never seeing his parents again. But the film's focus is mostly on the work itself.

"Painting is another form of thinking," Richter says, and as you watch him in action, you can actually glimpse his mind buzzing away.

Michael Upchurch: mupchurch@seattletimes.com