In the 53rd Street subway station, the posters for Olafur Eliasson’s forthcoming retrospective at the Museum of Modern Art hail commuters like a message from a spiritual adviser. “TAKE YOUR TIME,” the posters urge.

“Take your time,” besides being the title of a major new work in the exhibition, and of the exhibition itself, which opens Sunday, is a kind of catchphrase for Mr. Eliasson, expressing how he hopes that viewers will experience his art.

Mr. Eliasson, who doesn’t shy from the type of jargon used in Contemporary art seminars, said in an interview at MoMA yesterday: “There’s a tendency to generate a consumer aestheticism around art, which finds it profitable to deprive itself of temporality — where you say, ‘Experience! Boom! Here, it’s a spectacle!'” He made a hand gesture suggestive of slapping a painting on a wall — or, perhaps, on the cover of an auction catalog.

“The danger is by removing temporality you also remove individuality, because it is within temporality that you and I become different,” Mr. Eliasson said. In other words, as he said later: “We don’t see the same thing.”

Many works in the show, which will be on view at both MoMA and P.S.1 Contemporary Art Center in Queens, play on the viewer’s perceptions of light and color. “360° room for all colours” (2002) is a white circular room, in which a one-hour “narrative” of different colors plays along the walls. Some of the colors you see are actually being projected, and some are afterimages produced in your eye. Thus, if a person enters the room 30 seconds before or after a companion, each will see a different landscape of colors.

Mr. Eliasson convinced MoMA to extend the exhibition into transitional spaces around the galleries. A hallway connecting the architecture and design gallery to the special exhibitions gallery has been walled off to create a tunnel, which is lit from above with a series of yellow monofrequency lightbulbs. When you’re in the hallway, everything appears either yellow or in shades of black. Once you’ve been in the hallway for a while, your eyes adjust, and the naturally lit room at the end of the hall appears purple.

Mr. Eliasson regards the tunnel as a crucial threshold for the exhibition, and, naturally, the threshold has a duration. “The tunnel is 24 meters long,” Mr. Eliasson said. “When you’ve walked halfway, you have been in there for eight seconds, and your eyes have absorbed so much of the yellow light that the space at the end has turned purple, which is a knowledge you will be needing later.” Other details in the galleries — such as the scale of the doors, which are lower than elsewhere in the museum — are designed to produce a feeling of intimacy, and a relationship between the work and the scale of the human body.

“The nature of your engagement has a huge effect on how you see [the work],” Mr. Eliasson explained. “I’m very much in the hands of the spectator.”

Mr. Eliasson, who was born in Copenhagen and now runs a studio in Berlin, has projects in progress in many countries around the world. He has an installation in the foyer of the just-opened National Opera House in Oslo. He is designing a façade for a concert hall and conference center in Iceland.(Two pieces in “Take Your Time” represent stages of research for the façade, which is based on a mathematical formula for stacking hexagonal bricks so that there is no space in between.) At Bard College, a permanent outdoor installation called “The Parliament of Reality” is under construction and will open in the spring of 2009.

Here in New York City, Mr. Eliasson is preparing for “The New York City Waterfalls,” a project commissioned by the Public Art Fund, and presented in collaboration with the city, in which four 90-to-120-foot waterfalls will be erected this summer at sites within New York Harbor.

Mr. Eliasson said that his role at this point is to make sure that the project’s artistic qualities are maintained, and its “social ethical potential” fully explored. “I’m maintaining the depth of the project,” he said. “I’m making sure that we don’t exploit anything into a spectacle.”

But of course the waterfalls, which are being billed as the biggest public artwork since Christo and Jeanne-Claude’s “The Gates,” will be a spectacle. Crain’s reported last week that Circle Line Sightseeing Cruises is offering a $50,000 “Waterfalls”-linked package that includes a night in a luxury hotel, a private cruise in the harbor, and a gourmet meal onboard. Since then, the package has been expanded to include a “diamond waterfall necklace”; a spokesman for Circle Line said the total price of the package may go up.

“The scope of the project has its own life,” Mr. Eliasson acknowledged.

Even before the waterfalls make their debut, Mr. Eliasson is seeking ways for his art to become part of New Yorkers’ everyday environment. He said he considers the trip between MoMA and P.S.1 to be itself a part of the exhibition. He designed the posters in the subway, which will greet people arriving at either MoMA or P.S.1 via the E and V trains, and will appear in other stations around the city.

“Take Your Time” has already attracted some high-profile attention. Last week, Mr. Eliasson, whose work is often seen as commenting on global warming, gave a private 40-minute tour to Vice President Al Gore. Asked if the two are collaborating on a project, an assistant to Mr. Eliasson said she thought that it was “just a friendly visit.”