In an image-saturated world where gaudy pictures blast from computers, phones and televisions, the photos of St. Paul artist JoAnn Verburg are strikingly still, serene and spare: Italian olive groves shrouded in mist, her husband reading or napping, friends floating aimlessly in crystalline water. Such familiar and ephemeral subjects have captured Verburg's attention throughout her 30-year career, and they hang at the heart of her new show, "Present Tense," opening Saturday at Walker Art Center.

The exhibit is Verburg's first at the Walker, a Minneapolis institution to which many of her early images are deeply indebted. It was organized by the Museum of Modern Art in New York City, where it debuted in July.

In the early 1980s, after moving from Cambridge, Mass., to Minnesota, Verburg began photographing artists, especially dancers, in town to perform at the Walker. With their finely tuned awareness of movement and space, the dancers awakened in her a new understanding of the human body, its scale and how it inhabits the world. To this day, a signature element in her images is the inclusion of something life-sized: a glass of water, a tree branch, a newspaper, a body adrift in shimmering light.

Verburg, 57, recently recalled the excitement she felt in 1979 when she took the first of her life-sized photos. It was a portrait of a friend, Joel Janowitz, made with an experimental Polaroid camera to which she had access because she was managing an artists' program for the camera company. The camera took huge 20- by 24-inch images that were amazingly detailed.

"I took the photo home, put it up on the wall and kept looking at it; I couldn't do anything else," Verburg said.

Two years later she arrived in Minnesota to be an artist-in-residence at the Minneapolis College of Art and Design, where she continued to pursue portraiture, photographing performers Meredith Monk, Trisha Brown, Ping Chong, Robert Wilson and other avant-garde luminaries. A selection of those early black-and-white images will open the Walker show along with several of her "water pictures" -- images of friends swimming or floating in a skylit pool.

In "Present Tense," the show's elegant catalog (MOMA, $50), curator Susan Kismaric describes the images as being about people "at sea in the waves of emotions and instability created by relationships." She analyzes the swimmers' vulnerability and isolation as a metaphor for "the anxiety and doubt of modern experience."

Verburg works with large-format, old-fashioned cameras that are mounted on tripods and activated from under hoods. Many exposures take up to 45 minutes to set up and require infinite patience on the part of her subjects. Not surprisingly, her most frequent human subject is her husband, poet Jim Moore, whose ruminative behavior -- he apparently reads, writes and naps a lot -- lends itself naturally to slow-motion photography.

Beyond revealing the little pleasures of daily life -- or its tedium, depending on your point of view -- these images bring viewers into extraordinarily intimate contact with an otherwise private person, a comparative stranger whose balding pate, bare feet and damp tummy are now tenderly exposed to the public gaze. Verburg has lavished on her love the kind of attention usually reserved for the George Clooneys of the world.

The last gallery includes photos of water and little pyramids of white sand that seem at once eternally monumental and utterly fragile and transient. Verburg avoids overtly religious language, but acknowledges a spiritual moment in the show's conclusion. "At the end, it is beautiful and empty, a place where presence and absence are referenced in water and sand," she said.