In the here and now

SAN DIEGO — DASHES of white light flicked on one by one as the installation crew at the Museum of Contemporary Art San Diego worked its way across an expansive wall, mounting custom-built fluorescent fixtures in a syncopated, fragmented diagonal grid. On the eve of the museum's Robert Irwin exhibition, the largest since MoCA's retrospective in 1993, the 79-year-old artist, in trademark baseball cap and jeans, paced the space with barely tempered eagerness. A birth was imminent.

When the last of the lights on the 20-by-50-foot wall went on and the work was complete, Irwin's smile added at least another thousand kilowatts to the room. The wall had come alive in a calligraphic dance of brisk luminosity and shadowy echo, an homage to both spontaneity and order. "You just get swallowed up in it," Irwin beamed.

"Light and Space" was, for Irwin, the riskiest piece, the cutting edge in a show tracing his 50-year evolution from Abstract Expressionist painter to choreographer of ephemeral experience. He had mocked up a small version of the installation in the museum's residency studio (which he is the first to occupy), but conditions in that modest space differed dramatically from those in the large gallery. He wasn't at all sure what he would get when the work went full-scale.

Conditionality has been, ironically, the one unchanging characteristic of Irwin's work since the early 1970s. The L.A. born-and-bred artist had spent the '60s reducing the vocabulary of his work on canvas. He distilled fields of active, multicolored gestures to monochrome canvases with austere pairs of raised lines. The line paintings gave way to slightly curved canvases across which thousands of fine green and red dots appear to dissolve. His push toward pure presence advanced further with the disk paintings of 1967-69. Mounted more than a foot away from the wall, the convex disks seem to merge intangibly with it.

In 1971, Irwin gave up his Venice studio and turned away from making self-contained objects. He began creating "site-generated" installations, many using translucent white scrim, that responded to the scale, shape, surface, light and shadows of a particular space. Irwin's aims at the time have since remained central to his work: to heighten attention to the processes of perception, expand sensory awareness, reawaken wonder.