David Hockney keeps seeking new avenues of exploration

've never really thought of myself as a portraitist," David Hockney says, inspecting his handiwork on the walls of the Graham Gund Gallery at the Museum of Fine Arts. ''On the other hand, it's not a sideline. Nothing I do is a sideline."

His exhibition ''David Hockney Portraits" wasn't opening for another 10 days. But Hockney, who flew in from England the night before, was at the MFA at 8:15 that morning. ''It makes me feel a little old," he says of the experience of seeing 51 years of his work brought together.

The words ''old" and ''David Hockney" have rarely figured in the same sentence. At 68, he retains the exuberance that has always marked both his art and person. It's equally evident in the bright colors of his canvases, the merriment in his manner, the diversity of his pursuits -- not just painting and drawing, but photography, collage, stage design, art history, and optics. Each, as he says, has proven much more than a sideline.

''David is such an extraordinarily curious man, in the 18th-century sense of the word," says Amy Meyers, director of the Yale Center for British Art. ''Naturally he's going to have a very broad exploration of the full range of human experience. He stands as a giant among modern artists."

Like Andy Warhol on this side of the Atlantic, Hockney thrust the art world into the '60s. He was an art school Puck -- buoyant and boyish, a one-man Beatles -- with his oversize glasses, thick thatch of hair, and gaudy clothes. He was gay in both senses of the word. It made perfect sense he'd fetch up in Los Angeles. The '60s headed westward, like the sun, and so did Hockney.

The body's thicker now, the moon face fuller, the hair white. Slightly stooped, Hockney looks like an elder statesman -- but a subversive elder statesman. Yes, he's wearing a tweed jacket and cravat. But the cravat's knotted around a polo shirt, and a cornflower-blue handkerchief peeks out from the jacket. Best of all is the stick-on name tag on the middle of his sweater. Formal David Hockney is not.

He may well be the world's most famous living artist -- who's the competition: Andrew Wyeth? Robert Rauschenberg? -- but there's no crust to Hockney, no great-man airs. He combines California informality with north-of-England bluffness. He still has his Yorkshire accent, a furry, rolling thing rich with elongated o's and pursed u's. The sound of it makes him seem that much less forbidding.

''I'm not a totally respectable person," Hockney says with a big laugh. ''I never claimed to be. I'm polite to people, but," and his voice trails off into an even bigger laugh. Happy and chesty, it's a laugh with nothing to prove.

One obvious function of age is Hockney's deafness. He's worn hearing aids for a quarter-century. He functions well with them, he says, but adds that it's a struggle. ''You can hear, but the truth is you're working hard," he says.

''You go into yourself," Hockney says. ''I've always thought [deafness] made you see more. Being deaf, something must compensate a bit. Like if you're blind, sound does. Sound gives you space. Well, if you're going deaf, perhaps you have a heightened visual awareness of space."

Hockney is carrying the catalog to ''Cezanne in Provence," the exhibition that opened in Washington at the National Gallery of Art earlier this month. It's a sign of his engagement with art past as well as art present. Not that ''past" and ''present" are distinctions Hockney necessarily makes. ''All art is contemporary, if it's alive," Hockney says, ''and if it's not alive, what's the point of it?"

He recalls an unexpected encounter in a German museum last summer with nine paintings Picasso did in his final years. Late Picasso, Hockney says with equal parts deference and glee, ''makes everything else look constipated."

The MFA show includes several self-portraits. How does Hockney like sitting for others? He barks out a laugh. ''Ha! I've sat for Don Bachardy, R.B. Kitaj, but it was Lucian Freud where I sat. I sat for 130 hours: every morning from 8:30 to noon, for about three months. It was just before he was having his show at the Tate [in 2002]. I've known him a long time, for 40 years, and deeply admired him, always. . . .

''I was, of course, fascinated with his techniques. He did let me smoke. I said 3 1/2 hours is a long time if I'm not doing much. So we chatted, we talked. Whereas I work a lot quicker. If you're working fast, it's very, very concentrated, so I tend not to say anything. Well, Lucian's method is such that he'll talk. Naturally, lots of it was gossip. Everybody likes gossip. We know a lot of people together, so we had a lot to go on about."

It's not just while being painted that Hockney loves conversation. Hockney's engagement with painting is part of a much larger, and no less enthusiastic, engagement with the world.

''He is an incredible intellectual and entirely self-taught," says Lawrence Weschler, director of the New York Institute for the Humanities at New York University, a longtime friend of Hockney's who wrote the text for ''David Hockney Cameraworks." ''Intellectually, he's like a babbling brook: tumultuously, tumblingly alive, discovering things freshly," Weschler says. (There are two portraits of Weschler in the MFA show, and he'll be speaking about Hockney at the museum on Wednesday.)

''Well, I like to keep alive, frankly," Hockney says with a happy shrug when the breadth and energy of his interests are mentioned. What's so striking is that when he talks he never declaims: He actually converses. Hearing something he agrees with, he assents with an eager, murmury, ''Yeah, yeah, yeah, yeah." It's almost a chant. He's warming himself up to respond.

Over the course of 90 minutes, Hockney discusses much more than just his own art. He touches on the death of photography, ''The Simpsons," the splendors of the Grand Canyon, how completely Western culture ignores the Second Commandment, the struggle between idolatry and iconoclasm, why he prefers fax machines to e-mail (''I can think just as fast as I write"), the merits of Frank Gehry's Disney Concert Hall, Picasso's lack of interest in music, the relative lack of winter portraits in art history (''You have to kit yourself out -- and it gets cold out there after three or four hours!").

The last comment springs from his current project, painting seasonal landscapes in Yorkshire. Landscape, a genre he took up only a few years ago, is the latest Hockney non-sideline.

''One of the things I'm doing in Yorkshire," he says, ''is [finding out] how difficult it is to learn not to see like cameras, which has had such an effect on us. The camera sees everything at once. We don't. There's a hierarchy. Why do I pick out that thing [as opposed to] that thing [or] that thing?"

This summer, Hockney will finish the landscapes project. ''I'll ship them all to LA eventually," he says. ''That's where I have enough space to look at them all."

And after that? ''You get on to the next thing," Hockney says. ''Any artist will tell you he's really only interested in the stuff he's doing now. He will, always. It's true, and it should be like that."

The only time he's at a loss for words is when he's asked who'd play the lead in ''The David Hockney Story." It's not as if the man lacks opinions on movies. For many years, he was a passionate film buff. He's the subject of a celebrated documentary, ''A Bigger Splash." He and the director Ridley Scott were contemporaries at the Royal College of Art. Living in Los Angeles, he's known such Hollywood luminaries as Cary Grant, George Cukor, and Billy Wilder. One of the most memorable works in the exhibition is a photocollage of Wilder.

Finally, after laughing twice, Hockney has his answer. ''Well, you don't need to do it. Remember, the pictures on the walls aren't like movies. They don't move, they don't talk, and they'll last longer. They will last longer."

Mark Feeney can be reached at mfeeney@globe.com.