After substantial refurbishment, that monumental, ethereal work is now set to be installed at the San Diego Federal Courthouse at the end of this year. One can imagine it becoming a must-see work for contemporary art fans visiting Southern California. For now, though, New Yorkers looking to experience the Irwin touch are lucky enough to be able to head over to the Pace Gallery at 510 West 25th Street, where three columns by Mr. Irwin, each about 16 feet tall, are on view through Oct. 20 in a show called "Dotting the i's, Cross in the t's: Part II." (Another Irwin show, "Part I," is on view at Pace's 57th Street branch.)

When I met with Robert Irwin at the gallery earlier this month to profile him for The New York Observer, he was experimenting with different lighting arrangements. "These things sit on a delicate edge,” Mr. Irwin said at the time, as he figured out how he wanted them to look. Under certain lighting, they looked a bit yellow. At other moments, they almost completely vanished.

Each time I've visited the show since then, the columns have looked different, depending on the time of day and the weather conditions outside. They can elude the eye, but they can also be gloriously present, streaking light along the floors and walls, brightening up the space in unusual ways. It is a show worth seeing a few times, perhaps at both the start and end of a Chelsea visit, a barometer of sorts for observing just how much has changed in the air around us over a few hours without us ever even noticing it.

Installation view of "doting the i's and crossing the t's: part I," at Pace's 57th Street gallery through Oct. 20.

On a gray morning early last week, the artist Robert Irwin sat at one end of the cavernous Pace gallery in Chelsea and gazed out at his latest exhibition. The only things in it are three thin, 16-foot-tall transparent acrylic columns that, under certain lighting conditions, disappear. The opening reception was set for the following evening, and he was trying to figure out how the room would look when it was dark out. Every few minutes, his iPhone rang—a Pace employee on the roof, blacking out skylights.

“These things sit on a delicate edge,” Mr. Irwin said. “When it was bright in here, it was pretty yellow, and they get blown out. These things hardly existed at all. Is that good, or is it bad?” Pause. “I don’t know.” He sounded intrigued, rather than worried.

Irwin. (Courtesy Philipp Scholz Rittermann/Pace)

Though you wouldn’t necessarily guess it from his uniform of jeans, running shoes and a baseball cap (with a Coca-Cola logo that day), the San Diego–based Mr. Irwin, who turns 84 this month, is one of the America’s great aesthetic radicals: a MacArthur “Genius Grant” winner and a standout among the 1960s Light and Space artists (who are seeing renewed interest at the moment), he is arguably the most influential artist that California has ever produced.

He started out as an Abstract Expressionist painter in the 1950s, but made increasingly minimal work—paintings with only lines, then only dots, then simply discs that hover in space, their edges indistinguishable from the wall. He banished painterly marks, then the frame, then the painting itself. (“I painted myself right out of it,” he told me.) By the 1970s, he was producing installations composed only of light and subtle alterations to spaces. He also began venturing outdoors. For a show at the Whitney in 1977, he repainted the intersection of 44th Street and Fifth Avenue and strung a wire between the two World Trade Center buildings—artworks that few probably noticed.

“I was always asking myself, what is the actual goal of art, the actual subject of art? What justifies its high standing?” he said. “We’re building these cathedrals to art today, really almost to the level of absurdity, so you ask yourself, what does it contribute?” During his pauses, the muffled sound of a buzzsaw could be heard next door, where Pace is at work on a new cathedral, its fourth New York space. “I’m of the opinion that we are constantly discovering the world and that the point of art is that act.”

'Untitled (Acrylic Column),' 1969–2011.

Given this focus on discovery—“I’m a question addict,” he said—it seems odd that he’s taken a retrospective look at his career in his recent shows. In April, he opened “dotting the i’s & crossing the t’s: part I” at Pace’s 57th Street headquarters, which includes versions of works he’s presented over the past few years. His show in Chelsea is “part II,” and those acrylic sculptures are new versions of pieces that he first made in 1971.

Back in April, I met with Mr. Irwin at the 57th Street space, and asked him if “dotting the i’s” marked an end point. Was he retiring? “The shows are kind of summarizing some stuff, yeah,” he said offhandedly, then  launched into a breathless description of his new fluorescent light pieces, which he layers with gels used on theater lights to create unusual colors. One was on view in the show, and he said he’d been working on new ones that are even more complex. “I’m not actually closing up shop.”

In fact, he was just back from London, where, at the request of Pace founder Arne Glimcher, he had taken a look at a space at the Royal Academy that the gallery was considering turning into its London branch. (Pace has since signed a lease there.) Though he has no formal training in the field, he’s done his fair share of architectural projects over the past few decades, designing one of Pace’s Chelsea galleries, as well as the Dia Art Foundation’s museum in Beacon, N.Y., one of contemporary art’s most impressive cathedrals.

“Being an artist is really about a sensibility,” he explained in Chelsea. “It’s an awareness about the nature of things, on a base level. A sensibility is applicable to anything and everything. It’s a way of going. So I tested that by doing a garden.” He was talking about his garden at the Getty Center, which he made in the early 1990s. “I’m not a gardener. I had never planted a plant before in my life. Can an artist do that? Can I take my sensibility and make things with it?”

The Getty garden is a fairly baroque piece of landscape architecture, but in general Mr. Irwin’s sensibility tends toward subtle, unexpected touches. At the 57th Street show, he cut rectangles out of two windows. Few people appeared to notice them at the opening; the street noise was a bit louder than normal, and the light streaming in was different, but if you weren’t looking for the work, it was easy to miss. “I think its one of the better things I’ve ever done,” he told me, “in the sense that it’s so much what it is, and it’s kind of authorless. You don’t think about whether it’s art or not art. It’s just about what you’re seeing or not seeing.”

Detail view of '1° 2° 3° 4°' at Pace's 57th Street gallery.

And that—seeing—is the root of his art. When people walk into a room, he said, they “do an instant check, you know—you just want to make sure there’s no hole you’re going to fall into, there’s nothing you’re going to bump into, so you do that very quickly, we’re not even aware of it—it’s instant.”

At their best, Mr. Irwin’s artworks disrupt that reflex with an absolute economy of means. His acrylic columns just barely distort the view of the room; you may not notice them until a person vanishes while walking behind one. “You’re forced to stop for a second, to recheck, because something’s not right,” he said. “So you freeze, and in that moment of freezing, in a way, you become a first-time perceiver.”

All of this can sound a bit precious. The late critic Hilton Kramer said as much in the 1970s in The New York Times, writing, “Mr. Irwin casts himself in the role of an esthetic saint, who, having renounced the world of material art objects, has found salvation in a higher realm of pure perception.”

That would be a more convincing argument if Mr. Irwin’s art were not so immediately pleasing and accessible (once you notice it), and if he weren’t such an obsessive devotee of materials.

For a series of monochromatic paintings at 57th Street, he and his technical collaborator of 45 years, Jack Brogan, used honeycombed aluminum panel developed for airplanes. “You know, there’s flat and there’s flat,” Mr. Irwin said. “The wall’s flat, but those panels are absolutely flat, they don’t have any warp or weave in them.” He added, “They look very clean and simple, but they have probably 40 to 50 coats of paint on them, and they have been hand sanded probably 20, 25 times.”

When he and Mr. Brogan first made the acrylic columns 40 years ago, the largest available acrylic blocks were four feet in length, so building tall columns took some effort. They developed special compounds to polish the ends, and then carefully joined them together. Still, the seams were (just barely) visible from certain angles. “Even if you couldn’t see them, they were there,” Mr. Irwin said.

Installation view of "doting the i's and crossing the t's: part I."

But technology has improved. Today’s acrylic has a crisper, bluer color and is harder, which allows for smoother polishing, and blocks come in lengths of eight feet. The 16-footers in Chelsea have just one seam, and it’s impossible to see it. “It’s perfect,” he said. This innovation presents another conundrum, he happily admitted: is it better for a collector to acquire an earlier, more art historically important column, or a new, technologically advanced one? It’s the sort of question one asks more frequently of, say, cars than art.

“If I can make them more beautiful, you know, why not?” Mr. Irwin said by way of explanation. “I’m in the beauty business. I have never made anything in my life that was not as beautiful as I can make it.”

arusseth@observer.com

(All images of artworks © 2012 Robert Irwin/Artists Rights Society (ARS), New York, courtesy of the artist and the Pace Gallery, New York)

John Wesley, Nail Police, 2003. (Courtesy the artist and Fredericks & Freiser)

When artist Robert Irwin arrived by accident in Marfa, Texas, in the 1970s and saw the "magical" landscape, he got rid of everything he owned and started developing what he called "a conditional art," which is to "deal with the conditions as they're given to you." Mr. Irwin is one of 12 artists featured in "A Marfa Dozen," a slide show up at Vanity Fair of people who lived, worked or exhibited in the small town. 

While we've all heard a lot about Marfa, this slide show features a selection of artists with well-established and developing connections to Marfa. There's Dan Flavin who exhibited his light work at the Chinati Foundation in the mid-'90s as well as the aforementioned Mr. Irwin, who is also featured in a video on the site, who presented his installation Untitled (Four Walls) at a temporary space at the Chinati Foundation in 2006. The younger generation of Marfa artists includes Elmgreen & Dragset, whose 2005 installation of a Prada storefront, entitled Prada Marfa, looks perfectly real except for the fact that you can't enter it. And then there are a few former artists-in-residence of the Chinati Foundation, like John Wesley and Charline Von Heyl.

It's enough to make you want to rent a pickup and hit the road.

No install shots: go see the show.

Let's say you're a New Yorker in Europe right now. You've hit Manifesta and Documenta, plus made the requisite trips to Zurich and Basel. You're thinking about hanging around for another week or so to relax after all that art viewing. But wait, you realize in horror: you're going to miss seeing Robert Irwin's show at Pace's East 57th Street location, which ends its run on June 23!

No, you're not.

Pace just released word that the the exhibition has been extended through July 13. (The extension applies to everyone, including those who simply have not yet seen the show because of general procrastination or being very busy.)

It's always sad—and embarrassing—to miss a major exhibition, but this one would be especially tragic to miss because it is the first part in a double-header called "Dotting the i’s & Crossing the t’s." The second part arrives in the fall at Pace.

If you need further inducement, know this: it's a good-looking exhibition. Just a few handsome works—classic Irwin—elegantly arranged. Plus, he's made some subtle alterations to the space that are well worth the trip.

Update, June 20: An earlier version of this post incorrectly stated the extension of the show. It is hopen through July 13.

WEDNESDAY, APRIL 25

Gala: White Box
With all the galas we've got going around these days, you've really got to distinguish yourself somehow. The gala at White Box offers not only DJ Spooky and an auction fronted by Phillips de Pury & Company Celebrity Auctioneer CK Swett, but as if that weren't enough they're also Skype-ing in Ai Weiwei. Sounds like a party to us. —Dan Duray
White Box, 329 Broome Street, New York, 6–10 p.m., from $50

Opening: Robert Irwin, "Dotting the i’s & Crossing the t’s: Part 1," at Pace
The title of Robert Irwin's latest exhibition suggests that the great California artist is in a retrospective mood, revisiting work and ideas from throughout his career—which is wonderful since, over the past 60 years, he's charted one of the most remarkable, action-packed journeys of any contemporary artist. This show includes a new installation involving the gallery's windows and a light work. Part two arrives in September. —A.R.
The Pace Gallery, 32 East 57th Street, New York, 6–8 p.m.

Lecture: Lorraine O’Grady "Portrait of the Artist" presented by the Performa
The Performa Institute presents the first installment of a new lecture series, called Portrait of the Artist, featuring Lorraine O'Grady. Art historian Kellie Jones will present a look at Ms. O'Grady's work, followed by a conversation with the artist. —Michael H. Miller
NYU Einstein Auditorium, 34 Stuyvesant Street, New York, 6:30 p.m., free with reservation: rsvp@performa-arts.org.

Screening: "Found" at Eyebeam
Short films made by Fred Wilson, Christian Marclay, Rashaad Newsome and Jacob Ciocci comprise the first installment in a screening series curated from the Eyebeam archives by James O’Shea. This screening involves artists who work with found and appropriated images, a practice that is connected to Eyebeam’s philosophy of free and open culture. After the opening, the films will screen daily, beginning April 26, from 12-6 p.m. —Rozalia Jovanovic
Eyebeam, 540 West 21 Street, New York, 8:30 p.m.

THURSDAY, APRIL 26

Opening: David Benjamin Sherry, "Astral Desert" at Salon 94
David Benjamin Sherry went off the grid for a while to travel the National Parks of Utah, Nevada, New Mexico, Arizona and California. For his first solo show in New York, he presents a series of photographs, sand prints and photograms that he made while in the desert, using traditional medium and large format film cameras. This series of vivid portraits of desert sandscapes questions the dominance of digital imagery and honors the American West in wild colors.
Salon 94, 243 Bowery, New York, 6–8 p.m.

SATURDAY, APRIL 28

Opening: Sherrie Levine, "A Dazzle of Zebra" at Paula Cooper Gallery
Paula Cooper presents an exhibition of new work by Sherrie Levine. We're not sure what exactly to expect, but Ms. Levine is always enthralling. There's this little bit of info from the gallery as well: "Much like the exhibition’s title, Levine’s installation sets in motion an alliterative principle: the works rhyme with each other and with their counterparts in the 'real world.'" --M.H.M.
Paula Cooper Gallery, 534 West 21st Street, New York, 6–8 p.m.

SUNDAY, APRIL 29

Event: Columbia Visual Arts MFA Thesis Show
The second year Columbia MFA students show off their stuff before they go out into the world to get famous. Should be a blast. —D.D.
38-27 30th Street, Queens, 2-5 p.m.