Danish-Icelandic artist Olafur Eliasson (b. 1967) tends to focus on the simplest things, the most elemental phenomena. Wander through his room-size installations and you’ll find yourself largely alone with light: There is little to “look at” in his work, yet much to absorb. Perhaps that’s why his extensive, dual-venue exhibition — at both the Museum of Modern Art and P.S. 1 — his first comprehensive show in America, is called “Take your time.”

One would do well to heed the advice. The numerous large installations in the show foster, and repay, a contemplative approach. You can’t, for example, attend to the languid progression of colors, from magenta to blue to green, in his circular “360° room for all colours” (2002) in a rush. Indeed, time is essential in this show, in more ways than one.

But it is all too easy, especially at first, to be impatient. Mr. Eliasson is very much a northern temperament, a cool artist of the intellect, a man fascinated by science, geometry, and the chilly, boreal light of Iceland. And individually, many of his pieces can feel insubstantial — rich in art historical reference and conceptually solid, perhaps, but meager to behold. It is in the full sweep of the exhibition, in the accretion of sensory experience and generated ideas, that the power of this work is most thoroughly felt.

“Mirror door (user),” for example, consists of a mirror set on a wall and cut to the precise dimensions of a door opposite it. A spotlight on a tripod directs its light into the mirror, so that the tripod stands within the circle of light reflected on the floor in front of the mirror — in itself not much to see. But move to “Mirror door (spectator)” — in which the light is focused to create only a half circle, which is then completed by the mirror — and on to “Mirror door (visitor)” — where the tripod stands next to, rather than inside, the circle of light — and a charming and unexpected story begins to unfold.

Individually, any one of Mr. Eliasson’s “walls” might be taken as a compellingly zany, semi-decorative structure. A honeycomb of stainless-steel irregular, open hexagons, “Negative quasi brick wall” (2003), sits in a window, its mirror-polished facets reflecting the buildings across 54th Street. Alone, it appears to be a sort of postmodern decorative architectural flourish. Yet once you’ve seen “Soil quasi bricks” (2003) — solid hexagonal tiles made from highly compressed soil — covering the walls of a room at P.S. 1, you begin to think about the microscopic crystalline structure of the materials employed in our daily lives. And you begin to consider what one might call nature’s industrial look, how — when magnified — tiny structures in nature often resemble industrial creations. And then you might come upon the spongy “Moss wall” (1994), which looks like industrially produced white shag carpet stained from years of use.

Spatial context and temporal progression operate like knitting needles here to spin new stories from the oldest and most basic subjects. In “Jokla Series” (2004), we see a grid of 48 color prints presenting aerial views of contiguous segments of an Icelandic river. Each image adds a frame to the river’s meandering story. Roxana Marcoci and Klaus Biesenbach, the curators of this show for MoMA, call this sort of narrative progression “protocinematic vision” in a catalog essay. Somewhat more helpfully, the curators link Mr. Eliasson’s artistic practice with early 20th-century artists such as El Lissitzky and László Moholy-Nagy, who were interested in new optical techniques and cinema. They also discuss his work in relation to his more direct artistic forebears from the 1960s and ’70s, figures such as Robert Irwin and James Turrell, who are known for their work with light and space, and Robert Smithson, famous for pioneering earthworks such as “Spiral Jetty.”

Like Smithson and Mr. Turrell , who were concerned with bringing art out of the museum and into the natural environment, in a sense making the natural environment the work itself, Mr. Eliasson likes to shift the context in which we experience nature, or the external environment. This might involve building a wall of moss in the museum or, as in “Sunset kaleidoscope” (2005), looking out from the museum to the world outside. The latter piece is a mirrored box with a motorized colored disc inside, which, when one looks through it to the outside, causes an artificial sunset.

Mr. Eliasson tries also to alter the more traditional relationship between work and viewer: He creates immersive environments, pieces a viewer experiences from within. One bathes in a series of colors from hidden fluorescent lights in the room-sized “The natural light setup” (2008), while an intricate glass cylinder projects a moving spectrum on four walls in “I only see things when they move” (2004).

Still, some of the most successful pieces here — and certainly the crowd-pleasers — retain some type of image on which the viewer can focus. In the title piece, that image is the viewer’s own reflection in a room-filling circular mirror rotating on the ceiling. Other pieces employ water as the projection screen. Light hitting a curtain of mist forms stunning veils and rainbows of color in the aptly named “Beauty” (1993), and strobe lights seem to freeze the falling water droplets of “Your strange certainty still kept” (1996).

Although a bit unwieldy because of the two venues, “Take your time” is nevertheless an absorbing and very thoughtfully designed show. At P.S. 1, for example, you can poke around rooms of Mr. Eliasson’s maquettes and drawings, as if rummaging through the contents of his mind. And there, one might realize that, whether you behold it as an old-fashioned spectator or are immersed in it like an astronaut on a space walk, Mr. Eliasson’s work seeks to do exactly what art has always done: make you see the world from an altered perspective, to see it anew.

Until June 30 at MoMA (11 W. 53rd St., between Fifth and Sixth avenues, 212-708-9400) and P.S. 1 (22-25 Jackson Ave. at the intersection of 46th Ave., 718-784-2084).