Tacita Dean: Craneway Event, Frith Street Gallery

Silhouetted against the sparkling waters of San Francisco Bay, a pelican surveys the scene from a quayside bollard, then takes flight. The beautiful opening shot of Tacita Dean’s Craneway Event establishes a mood of elegiac tranquility. We are at Ford Point, on the east shore of the bay, in a magnificent building – a Ford factory that made military vehicles in World War Two, but closed down in 1955. Floor to ceiling windows afford breathtaking views across the water and allow the California light to flood in, transforming the floor into a liquid sheen of shadows and reflections.

In November 2008, Dean spent three days filming the late Merce Cunningham (pictured below) and his company rehearsing an anthology of key sequences chosen from his vast repertoire of choreographic innovations. Day one seems a bit shambolic; the dancers wander in and limber up before the 90-year-old choreographer arrives in a wheelchair to conduct proceedings.

The performers already know their moves; its their orientation within the vast space that needs finessing. “OK, go!” yells Cunningham and they file in to take their places in front of the steel buttresses lining one wall. They spring into action without music (it will be added later) and rely on counting to keep time. But with a soundtrack of creaking floors, scuffling feet and heavy breathing, their efforts seem more like a strenuous workout than a dance.

The camera lingers on Cunningham as he watches, making notes on sheets of paper bearing titles such as “Points in Space”, “Scramble” and “Changing Step Solo”. Sometimes the view through the window takes precedence: a sailing boat glides by, a motorboat buffets the water and a ferry chugs across the bay. The rehearsal draws to a close, the company clusters round his wheelchair for an appraisal, and the setting sun casts long shadows across the empty floor. It has been a day well spent.

Day two begins with a giant tanker sliding silently past the quay, while a dancer has a quick smoke. Indoors, we watch the opening sequence from a different viewpoint, then the focus switches to the transitional passages. Silhouetted against the light, the dancers appear like marionettes framed within grids of glass and steel. As they leap and spin through space, one begins to think of the building as a container or vessel and the performers as ephemeral beings briefly passing through.

Like the architecture, the static camera provides a fixed frame of reference, a sense of stability against which to view the incidental flux and flow of daily life – a boat docking outside the window and a pigeon waddling around the dance floor while, darting in and out of shot, the performers create a dialogue between transience and permanence, movement and stasis. “I don’t often pan in my films,” Dean remarks. “I like things to happen within the frame; I prefer to wait for it. It’s an aesthetic thing.”

As the sun traverses the sky, the dancers repeat their moves and Cunningham snatches an afternoon snooze. One becomes increasingly aware of time, the element in which we swim and have our being, and of light as the medium that makes it visible.

On day three, the dancers perform the 90-minute piece in its entirety, but their efforts now seem peripheral to the main subject, time – the length of a day, the duration of a project, the span of a human life – and the main event, light. It invades the space, reducing the dancers to doll-like silhouettes and dissolving their limbs in its rays.

Light, of course, is the element on which film relies. “That beautiful, incandescent material” has been the artist’s chosen medium ever since she was a student at Falmouth and the Slade. “People portray me as a fetishist,” she tells me, because she refuses to switch from 16mm to video, “but I simply prefer the quality of film.”

Each magazine contains 10 minutes of film, so the camera has to be constantly reloaded, and after three days Dean had 17 hours of discontinuous footage. Not surprisingly, she insists “the real process is in the editing” and shows me the Steinbeck on which she spent months in her Berlin studio meticulously cutting and pasting the reel-to-reel footage into a feature-length film.

Sadly, Merce Cunningham died in July 2009 before the editing was finished and, as the last film on which he collaborated, Craneway Event has inevitably acquired the status of a tribute or an epitaph. In its extraordinary beauty, Tacita Dean’s film lives up to the role; much more than a record of a rehearsal, it is a meditation on the achievements and working methods of a man who spent his long life striving for creative excellence.

• Tacita Dean: Craneway Event is at Frith Street Gallery until June 23. Check website for screening times
• Merce Cunningham Dance Company website