The Ralston Crawford we encounter in his exhibition at the art gallery of the University of Maryland in College Park is not the Crawford we thought we knew. Crawford (1906-1978) is, of course, best known as a painter of Precisionist oils. His photographs, less familiar, dominate this show.

These photographs, the best of them at least, are less arid and more moving than the crisply painted pictures of industrial America that earned him his fame. His canvases are people-less, rational and strict. The finest of his photographs surprise because they're open to a wholly different spirit. Crawford's photos are humane.

The messiness of human life is something Crawford intentionally excluded from his hard-edged paintings. Their subjects are inanimate. They typically portray bridge abutments, docks, brick walls, urban rooftops and tank farms all lit by a light that is the light of reason.

In his photography one feels the stirrings of his heart.

And the tapping of his foot and the warmth of his affections. The nicest of his photographs are about jazz. Most were made in the decaying streets and smoky dives of black New Orleans. Their mood is one of welcome. They make no effort to exclude the detritus of life--the checkered dishcloth in the corner, the comics on the easy chair, the five wire hangers on the nail in the wall. That woman blind with booze is viewed without condemnation. The people in these photographs--the housewives and the barflies, the dancers and musicians--never seem to mind the clicking of the shutter.

Crawford's life was full. Born in Ontario, he went to sea at 19, then worked in California drawing Oswald the Rabbit for Walt Disney, and then studied art in Philadelphia, New York and Paris before he settled down to paint.

Crawford began photographing seriously in 1938. At first he used the camera as many painters do, as a kind of sketch machine. He would photograph an object--the Maitland Bridge, the Third Avenue el, the docks in New Orleans--from this angle and that, until he found a composition he could closely reproduce in an oil painting. "I firmly believe," he wrote, "that a prolonged study and shooting of a subject from various angles and distances under several light conditions is highly rewarding . . . This is not drudgery, but an interesting activity all the way. You will make illuminating discoveries."

He painted slowly, his canvases seem timeless. His photographs, in contrast, respond to the instant--that smile will soon pass, that shadow will soon move. And yet there still is something--an unwavering integrity, a concentrated seeing--that all his pictures share.

He was one of those rare painters--like Eakins, Degas, Ben Shahn, Man Ray, and, now, David Hockney--who understood the difference between painting and photography, and knew how to do both.

A number of these phototographs, particularly the early ones, prompted oil paintings. The curving shadows and white pipes of his "Sanford Gas Tanks" (a photograph he made in 1938) would soon appear again in "Sanford Tanks," a painting now on view in "Images of America: Precisionist Painting and Modern Photography" at the Baltimore Museum of Art. Although many details--the ladders and the cat walks, the rivets and the weeds--have been excluded from the canvas, the compositions are the same. The angles of the el and the smooth piers of the Maitland Bridge also led to paintings.

Crawford, in his early photographs, sought out the clean-cut, the slice of a diagonal, the grid of a fac,ade. His jazz photographs are different. They seem wholly self-sufficient, and vastly more inclusive. They were not made for paintings. They were made for themselves.

In them, Crawford's vision is as sharp, his focus as clean, as in the paintings. He had not lost his fondness for white highlights against shadow, for centered compositions or the rhyming of right angles. But present in these photographs is something absent from his canvases, a sense of life and warmth, of community, of soul. The strictest of his paintings have a certain wit. His photographs of black people in New Orleans are pictures shot with both absolute control and unembarrassed love. "One forgets that they haven't got a dime," he wrote. "The qualities that one cares about are the great security and sometimes nobility of these people."

The last photographs he made, though handsome and complex, are less compelling. Near-abstractions of shadows on walls, or crumpled cars, or peeling, weathered signs (a la Aaron Siskind), they call to mind too many other photographs made by other hands.

Crawford deserves to be remembered mostly for his photographs of New Orleans, for his hard-edged Precisionist paintings and for the qualities of mind--the clearsightedness, the patience, the concentrated looking--that allowed him to make both.

"Ralston Crawford: Photographs/Art and Process" was organized jointly by photographer John Gossage, who teaches at Maryland, and by Edith A. Tonelli, who now directs the gallery at the University of California at Los Angeles. The show closes May 1.