Frederick Wiseman turns his extraordinarily observant camera on people-as-things in "Model," the ninth documentary he has made for the Public Broadcasting Service through WNET in New York. The sexy subject matter and its built-in ironies make this Wiseman film much less dry and much more accessible -- despite its two-hour, 10-minute length -- than such latter-day Wiseman works as "Canal Zone" and "Sinai Field Mission."

Wiseman is not only a thoroughly distinctive filmmaker but virtually a genre unto himself. Without narration (like all his films) and without bending over backwards, or even sideways, to make a point, "Model," at 8 tonight on Channel 26, penetrates the image jungle of marketable faces and figures and makes subtle, textured commentary on modern American voyeurism and the objectification of human beings in the name of commerce. This is an essay on the beheld, the beholders, and the beholden.

Various sequences -- backstage at a fashion show, on the set of a panty-hose commercial, at posing sessions -- are bridged with the visual equivalent of ambient sound, seemingly random street scenes of New York on the move. What is on the move is not just cars and trucks and people but commerce, and not on little cat's feet, either. Men and women strive and yearn to be turned into icons in the service of this great god; it is the almighty camera that can certify and immortalize (for 15 minutes, anyway) and canonize them.

The film opens with scene-setting shots of the city; the ebb and flow of humanity is watched from on high, from a billboard, by the Calvin Klein jeans man, who is disinterested, and perfect, and literally above it all. From everywhere in the city these heavenly, heavily prepared faces and bodies look out, alluring and intimidating.

They appear to be free of guilt, free of flaws, free of thought. A photographer shooting a fashion spread tells the three slinky women in the coats and hats to act like "you're in Bloomingdale's window," like "mannequins." In a world that seems to grow increasingly visual and decreasingly literate, increasingly body-conscious and decreasingly brain-conscious, these pod-people are held up everywhere as the ideal. They have reached a neuterized version of nirvana, a blank peace.

"Oh God, that's great, holy damn, we got it!" shouts a female photographer to a male model named "Romeo" who is standing death-still with a shiny watchband prominently grasping his wrist. "La la la la la la! . . . Oh God, that's nice! . . . Romeo, yer knockin' it out! "

"Love it, love it, love that face," says a male photographer to a female model. "Keep that excitement now . . . A little more sophisticated now . . . Just a little more innocent, a little more sexual, okay?"

At Manhattan's Zoli agency, hopefuls arrive with Their Books. A young male model is told he must project "a lot of high energy, lots of smiles." A 19-year-old woman, 5 feet 6 1/2 inches tall, is told she won't do because she is half an inch too short. On the phone, agency representatives say such things to models and clients as, "Yeah, average, all-American-beautiful, right" and "Can you use a trampoline without killing yourself?"

Of course, a world built around artifice is an artificial world, but Wiseman is hardly playing the aghast moralist. He does concentrate on episodes that speak volumes about emptiness, especially in the documentary's equivalent of a production number, the filming of a commercial for "Evan Picone, the well-dressed leg," which required hours of location shooting and then arduous special effects for which a model must dangle her panty-hosed leg in front of the camera in a studio.

"It's probably the most difficult art form there is," says the director of the commercial.

Crowds of women walking down the street with placards turn out to be extras in the commercial, but later, there is a real demonstration near another shoot. Wiseman's juxtapositions are not always as subtle as may be expected of him, but usually they are either nifty or deep. While filming on location, he wanders among the faces of onlookers, the real people who can be identified by their rumples and wrinkles and a certain unlacquered look.

Whether to find the models themselves merely curious or appalling -- Wiseman leaves that to the individual viewer. Occasionally, it is startling to see a face familiar from frozen poses in print ads suddenly talk and laugh and break into animation. A famous male black model seems to explode like something out of "Star Wars" when he laughs; he tells a crew from the Andy Warhol factory that he would model nude "for an incredible amount of money."

Another model, asked what he thinks, replies, "I don't think." It is said proudly, like a declaration of principle. "Model" makes mercurial points with scintillating clarity.