Installation artist, sculptor, painter, and landscape designer. Best known for installations that combine scrims and illumination to create perceptually puzzling, dematerialized visual experiences, he claims the process of seeing as his subject. Since about 1980, he has also worked on large public art projects, with special attention to gardens. Born in Long Beach, California, Robert Walter Irwin began his professional training in 1948 at the Otis Art Institute (now Otis College of Art and Design) in Los Angeles. Two years later, he continued at the now defunct Jepson Art Institute but eventually completed his education at the Chouinard Art Institute (now California Institute of the Arts) in 1954. After painting in an abstract expressionist style, in the early 1960s he engaged in increasingly minimalist experiments. A few years later, he abandoned painting to concentrate on a series of Discs, shown under precise illumination in order to activate highlighted and shadowed surrounding spaces as part of each work. In the late 1960s he did away with physical objects altogether, concentrating instead on singular installations that focused attention on mysterious visual effects. During this period, he worked on problems of visual perception in the Los Angeles County Museum of Art's Art & Technology Program with physiological psychologist Edward Wortz (who remained a collaborator for years afterward) and, for about a year and a half, James Turrell. In recent years, he has devoted much attention to public sites, relishing the opportunity to shape environments and enhance viewers' comprehension of their visual and spatial qualities. Between 1992 and 1997 he designed the new Getty Center's outdoor environment in Los Angeles, creating a lush spill of foliage, flowers, and walkways down its adjacent hillside. For the Dia Foundation exhibition space (opened 2003) in Beacon, New York, overlooking the Hudson River, he devised a master plan to enrich every facet of the visitor's experience of the building and grounds, in addition to designing its formal gardens. Upon leaving Los Angeles, Irwin lived for a time in Las Vegas before settling permanently in San Diego in the early 1980s. Being and Circumstance: Notes Toward a Conditional Art (1985) introduces his theoretical notions.