Those who once dismissed semi-famous Norman Bluhm as a semi-gifted artist should see his recent oils at the Corcoran Gallery of Art. Bluhm has found his way. Something generous and elemental, a passionate exhuberance, blooms and rolls in his huge pictures. He has, at last, as 57, become a splendid painter.

Bluhm used to be described as a second generation abstract expressionist. That was not a term of praise. Pollock, Kline, de Kooning, the founders of the style, were widely viewed as heroes, but their followers were legion, and most of them were lousy. As quickly as it flared, action painting faded, spawning as it did countless messy canvases. Most were decadent and tepid, second-hand and second-rate.

Bluhm came to New York with rich art credentials. In Chicago, in the '30s, he'd studied with Mies van der Rohe; in Paris, in the '40s, he knew Mme, Henri Matisse, Camus and Cocleau; he's shared a studio with Sam Francis, and beery afternoons, at the Cedear bar, with Kline and Pollock (he calls them Franz and Jackson). But his timing was not good. His first Manhattan one-man show opened at Castelli's just after Pollock died. The fashion was already turning. The hard edge was ascendant, cool was coming in.

Despite his days with Mies, Bluhm's art was never cool. He employs huge quantities of paint, he hurls it and it splatters. When he wields the brush, he uses his whole arm. He is still an action painter. What has altered in the past few years, is the subject of his art.

His early works were violent, angular and thrusting. The mood they cast was macho. His new works at the Corcoran pay homage to the feminine. No longer does one read them as confrontational abstractions. They are made with love.

Before one reads their titles - "Sand Lady," "Coney Island Beauty," "Ripe Summer," "Salome" - one sees the goddess in them, her billowing, her warmth, her curving, fertile flesh. Bluhm says that for years he's been drawing from the nude. From her he takes his rhythms. Those who wish to label may call these works abstractions, but their colors are the colors of sunny sand and skin, their shapes evoke the figure, and their freely looping lines suggest not attack, but stroking.

They are, despite their warmth, paintings of terrific power. They force one to stand back, not from fear but from politeness. Bluhm, who's paid his dues, has at last become a liberated painter.

The SCM Corporation (a conglomerate whose SC comes from Smith-Corona) paid for Bluhm exhibit and will pay for other Corcoran painting shows "each concentrating on one cycle of work by one artist." Though the Bluhm show is the winner, five other exhibitions also go on view today at the Corcoran Gallery of Art.

"Gabriel Kohn: 1910-1975" surveys the chunky, oddly moving works of laminated wood made by the late sculptor. "Washington Today" includes drawings of this city, its citizens and monuments, all made by area high school students. In the back corridor, where it probably belongs, is another local exhibition, this one of advertising and commercial art. Two exhibitions of photography are also on display.

Washington's Frank Di Perna, who teaches at the Northern Virginia Community College and at the Corcoran School of Art, is one of those photographers - and there are not many - who does more impressive work in color than in black and white.

Earlier this year, at Diane Brown's, on P Street, he showed photographs of Mexico that, though always handsome and technically proficient, suggested other images - surrealistic travel shots of the surreal tropics - that one had seen before. Fresher by far are the small Polaroid SX-70 photographs currently on view.

What I liked best about his show is not the way he balances the "fictional" and the "real" "fictional" flowers printed on the fabric of a "real" sofa, a "real" auto parked beside a "fictional" swimming pool (painted on a wall), nor the formal rigor of his strict verticals and horizontals. Both of these conventions are, by now, familiar. What is most impressive here, what makes these works original, is Di Perna's use of color. The color is neither flashy nor extraneous. A number of these photographs, despite the strong geometrics of their compositions, would lose their real virtues, would simply fall apart, if they were black and white.

Like old furniture and old paintings, photographs, if old enough, seem stamped with their time. "Pioneer Photographers of Brazil" eerily evokes the past of that exotic country. Without cars or paving, traffic signs or lampposts, the dusty village suares seem oddly empty. The 19th-century aristocrats, and the aborigines, strike poses just as stiff as those in 19-the century statues. The rough hills, the sea, seem to show a land that man felt needed conquering.

Curator John Livingston wrote the intelligent catalog introductions for the Bluhm, Kohn, and Di Perna shows. The Brazilian exhibition was organized by the Center for Inter-American Relations. ("Rare Brazilian Photographs from the "Oliveira Lima Library," another exhibition with a similar them, will open here June 10 at the gallery of the Brazilian-American Cultural Institute, 4201 Connecticut Ave, NW.)