Artist Robert Frank -- that truthful, non-commercial, melancholy master whose volume "The Americans" is one of the chief monuments of mid-20th-century photography -- is donating a vast archive of his work to the National Gallery of Art.

His gift includes his negatives (some 2,000 rolls of film), scores of vintage exhibition prints, his rarest handmade book, 2,296 contact sheets and 999 work prints. No other institution has a comparable holding. Frank's immense donation -- which surveys more than 40 years of work -- will make the Washington museum the premier center for the study of his art.

Frank's photographs of the '50s -- of jukeboxes and cars, waitresses and workers -- changed the look of so-called "straight" photography. They blended reportage with poetry, and somehow gave encountered facts the poignancy of laments.

In accepting his donation, the gallery has granted him a signal recognition. Frank, 65, is the first living photographer to see his pictures enter that museum's permanent collection.

He joins exalted company. Since it opened to the public in 1941, the gallery has been willing to collect the work of only five photographers.

The first was Alfred Stieglitz (1864-1946), the influential artist-dealer. In 1949, his widow, Georgia O'Keeffe, urged on by Duncan Phillips, gave Stieglitz's "key set" of his most important prints to the National Gallery of Art. Nearly 40 years would pass before the gallery accepted photographs again, in this case a "museum set" of prints by Ansel Adams (1902-1984) printed from old negatives in the last years of his life. The third artist to enter the collection was Paul Strand (1890-1976), a Stieglitz disciple who moved from classical modernism to "straight" photography. The fourth was Walker Evans (1903-1975), the precisionist Yankee documentarian whose great book of the 1930s, "American Photographs," had a clear and profound influence on his friend, and one-time employee, the young Robert Frank.

The gallery was first approached, on Frank's behalf, by his friend Philip Brookman, the photographer and scholar who is now director of programs at the Washington Project for the Arts.

Selections from Frank's gift will be shown in an exhibition -- to be curated by Brookman and the gallery's curator of photographs, Sarah Greenough -- that the gallery will open in 1992.

It was while Brookman's wife, Amy, and Frank's wife, the artist June Leaf, were visiting the gallery about a year ago that the idea of the gift was first tentatively suggested. "Robert ought to see this place," said Leaf.

Frank, reached yesterday at his Nova Scotia home, said that the donation was his wife's idea. "We were just sitting around one day, talking of my photographs. I was tired of looking at them. I didn't take very good care of them, and I was tired of thinking about the past all the time. My wife said, 'Why don't you consider the National Gallery?' So I came down to see it. It's a most impressive place. I was impressed by the people too." Frank was also struck by the fact that the gallery collects very few photographers. "I didn't want my work thrown into a pool stocked with hundreds of big fish. Eventually, the whole thing clicked."

Though the gallery will not estimate the value of his gift, vintage prints by Frank are extremely rare, and some have sold at auction for $20,000 each. Though his donation must have a market value of several million dollars, under current tax laws the artist stands to gain almost nothing from his gift.

That's the way he wanted it. When Frank immigrated to America at the age of 22, it was not to earn his fortune. Frank was raised in Zurich, a city that loves money, but he has never yearned for wealth. "I think what I learned as I grew up was all negative," he has said. "I didn't want to be a businessman, to make more money, to buy a better house, a fur coat." He still prefers to live either in the sticks, in the tiny town of Mabou on Cape Breton Island, Nova Scotia, or in what some would call the slums, on the Lower East Side of Manhattan. Had someone else -- a dealer, a collector, a relative or friend -- presented 1,000 prints by Robert Frank to a national museum, that person could have earned a massive tax deduction. But Frank, as the artist, is able to deduct only the cost of his materials, the trivial sums he has spent on chemicals and film and paper for his prints.

His distrust for sharp dealing, for the over-dressed, the chic, is everywhere apparent in the spirit of his art. In his pictures of the '50s, the period's smug postwar prosperity feels eerily unreal. His art in those days conjured up the sort of life one sees through grimy city windows, the loneliness of highways, disillusioned dreams. Frank hung out with the Beats then, with Allen Ginsberg, Gregory Corso, Neal Cassady, Peter Orlofsky. Jack Kerouac wrote the introduction to "The Americans" and read the narration for the movie "Pull My Daisy" (1959), which was photographed by Frank.

"Being Jewish and living with the threat of Hitler must have been a big part of my understanding of people that were put down or held back," he's said. "And I think it's never left me. I do have a tremendous sympathy for people who are poor."

In announcing Frank's donation, Sarah Greenough described him as "the most important and influential photographer of his generation."

But not all specialists in the field share her high opinion. Frank's disdain for preciousness, for flawless focused prints, irritated many. His photographs, complained critic Andrew Goldsmith when "The Americans" appeared, "are flawed by meaningless blur, grain, muddy exposure, drunken horizons and general sloppiness." Idealogues were also troubled by his art. When he photographed Americans on the fringes of society, motorcycle gangs, gays and transvestites, he did so without lecturing. He had no ax to grind.

It is therefore not surprising that many of the money men who help control the photography market regard him with distrust. Frank, in turn, has long viewed the market -- with its coy manipulations, its love of stars and cash and chic -- with a deep disdain verging on disgust.

In the early 1970s, Frank experimented briefly with large-scale marketing of his prints. "The whole experience was disappointing. I found the people involved very unpleasant. Also, I got screwed. And I vowed I'd never deal with that sort of thing again."

Frank, unlike, say, Ansel Adams, has never shown much interest in using his old negatives to mass produce examples of his best-known prints. He has permitted no new prints of old images in the past 10 years. "I don't want to go back, to become a little factory making Robert Franks," he said. "I trust the gallery. I trust Sarah Greenough. Anyway, it's all written down in the deed of gift. I know that after I'm gone, they will not mass-produce my prints."

His donation includes a copy of "Black, White and Things" (1952), a handmade book of photographs -- shot in New York, Paris, London, Spain and Peru -- whose sequences, and subjects, seem in eerie ways to predict "The Americans." The early book is very rare. Only four copies exist. Frank has also given the photographs he calls "People You Don't See," a series of images of his neighbors on 11th Street in Manhattan. "People You Don't See" was submitted to Life magazine's "Young Photographers Contest," and took second prize.

The vintage prints donated include an unforgettable image of a little girl running past a hearse on a rain-slicked London street. The hearse's door is open, and through its engraved glass one sees a London dustman sweeping the wet street. The movement of the girl suggests a flight from death.

The image is, by now, well known. What is vastly less familiar is the contact sheet from which the print was chosen. That contact sheet is also included in the gift. We feel the artist, first, wandering through North London, among its grim Victorian houses, its mists and nearly empty streets. Frank first sees the hearse, and the coffin being loaded in. We watch as he approaches. He photographs the shiny grill and the long black hood. And then he takes one step to the left, and shoots, and the picture's done.

Greenough has said that "to be able to look at his negatives, contact sheets and work prints is like looking over his shoulder as he worked, recreating not only his journeys but his processes of thought."

Certain subjects reappear almost from the start -- tubas, street processions, the backs of passers-by, shiny cars, the open road. These shots are not set up, they are discovered. And yet one feels in all of them an odd, surreal haunting, as if the artist had combined the offerings of the real world with the darkness of his dreams.

"The truth is somewhere between the documentary and the fictional," he's said, "and that's what I try to show."

Frank's most recent images depend less on the sights he's seen -- that cowboy by a trash can, that white-clad preacher by the river -- than they do on the inner workings of his heart. Only very rarely now does he make "pure" photographs. Only recently, he took a pile of old images, pictures that he could have sold had he wished to do so, and nailed them to plywood and impaled them on a spike. He writes legends on his pictures now, or glues three or four together.

One recent work includes the phrase: "More spirit less taste. Remember. Keep going."

Frank may be the least guarded of 20th-century masters. His art is never armored by easy knowing irony, aristocratic distance or emotional reserve. It has been naked from the start.

A brief text from Antoine de Saint-Exupery begins "Black, White and Things." It reads:

It is only with the heart that one can see rightly

What is essential is invisible to the eye.