The ghost of actuality adheres to photography as closely as silvering to the back of a mirror. This anchoring to actual external phenomena, to found narrative, is photography's limiting curse—relative to other arts, it is rigid, obstinate to the supplications and manipulations of imagination—and the source of its special power and authority. A photograph convinces because it doesn't try very hard to do so—the strength of its proposition is matter-of-fact, even limpid. A photograph seems to have passively "discovered" its content rather than created and asserted it.

This explains why defensive efforts to "improve" photography through obsessive emphasis on technique, dramatic exaggeration, excesses in coloration, elaborate constructed narrative, appropriation of the styles of painting and other more traditionally "distinguished" art forms so often appear vain and counterproductive.

Jerome Liebling, well-known photographer and influential former Hampshire College professor, now 84, alludes to these fundamental issues in the title of his exhibit in The Nixon Gallery at the Smith College Museum of Art: Seeing Real Things.

In some ways, the show has the feel of a retrospective—the work spans four decades—but there is a definite emphasis on the later, more complex color work. There has been a tendency to slot Liebling in the lefty/liberal school of photography, as an heir to Roosevelt-era Farm Security Administration photographers such as Dorothea Lange and Ben Shahn, and to the universalist humanism of Edward Steichen's 1955 The Family of Man exhibit. The show may be a way to nudge his reputation out of that pigeonhole, an assertion of a modern sensibility and pertinence. Not that there's anything (aside from occasional predictability and preachiness) very wrong with the tradition: it has produced volumes of astonishing work, and Liebling is in fact an honorable heir to it, but it's clear that art comes first, and politics a distant second. The pigeonholing of politically engaged photographers is a tradition in itself—a convenient way to dismiss them. The great Walker Evan is an FSA photographer who gets similarly lumped in with the "socialistic" school, but his work is important as modern art not because it's political, but because it's bracingly cynical.

Liebling has been called a "documentary photographer"— probably more often than he likes—and it is a limiting description. His aesthetic is derived more from late 19th- and early 20th-century literature (Flaubert and early Joyce, for instance) than from visual traditions, although one can see Goya, Chagall, and Hopper in the mix as well. Liebling's work could be more accurately termed "expressive realism." Evans too rejected the label of "documentary photographer," claiming sneakily that he worked in the "documentary style," a big umbrella.

Liebling's earliest works in this show—from the late 1940s—are small black-and-white silver gelatin prints. They have a charming modesty and intimacy, and at times, for works so small and plain, a surprising intricacy. "Boy, Bandage, Fence, NYC, 1949" is as matter-of-fact and unfathomably mysterious as the best of his later work. The late Andre Kertesz, art photographer and founding father of photojournalism, liked his pictures small. He said it was good to be able to hold a photograph in your hand, suggesting that the proper aesthetic for approaching the medium was as a fond remembrance, something suitable for a family album. Liebling's little black and whites are engaging in this way, and stand in contrast (in their relation to the viewer) to the big color pictures that occupy most of the space.

If viewing little pictures is like a chat with a friend, then big pictures are a kind of rock 'n' roll. With small art, you go forward confidingly to meet it; big art comes at you with an air of challenge. Mr. Liebling's color photographs fall somewhere in between—electrified folk?—but they have an air of declaration, volume and assertion. To move between the small and large in this show is to receive a lesson in the relational physics of art viewing, an illustration of how size, small and large, matters.

There are also four very large older black and white photographs in the show. Two are from a chilling series shot in a slaughterhouse. One is an extremely finely-detailed portrait of a Native American woman in a restaurant. One is a mammoth print of what has become Mr. Liebling's iconic, most-published picture, "Boy and Car, Easter Sunday, NYC 1949": an elegant, tattered young black boy standing in front of an elegant, rusting automobile. The picture has subtlety and complexity, but it also is perhaps too easily appealing in the Life magazine sort of way. It's hard to say that this is a limitation; maybe we all just carry too many of these "archetypal" images around in our heads, and can't see it clearly. One can, however, discover in this picture an unequivocal liability of the digital printing of black and white photographs: get close and look at the whites of the boy's eyes. They are too stark and too white, hard-edged, as if pasted on. Of course the picture is optimally viewed at a certain distance—from at least 10 feet away—and most likely the picture was printed this way to be effective at that distance.

This is a genuine pitfall of really big artworks: they must play well at all removes. A small picture seen from afar simply "can't be seen"; a big picture looked at closely—and to look closely is the human inclination—is sometimes seen too well. In the same way that the digital rendition of music is said by some to lack soul, digital rendition of the visual can be too good, too controlled, perfected and clean. The eye and the ear are, after all, analog organs—it may be that the imperfection and softness of analog simulation is naturally more appealing; when it comes to representational art, a deficit in clarity may be, to our senses, more real.

The bulk of the show—and this is surprising, given Liebling's solid reputation in the annals of photography for the black-and-white work he produced in the 1950s and '60s—is relatively recent color work. It is a pleasure, a worthy challenge, to behold. The subject matter moves between pastoral simplicity and urban intricacy, but the photographer's outlook is deeper than that. The orchards and farmland, serene on the surface, exemplary in their straightforward rendition, are disturbed by something lurking and mysterious—in the midst of their lushness, there's an attenuation, a dead-end quality, literally, at times, a vanishing perspective: call it mortality. Whether this is due to the photographer's awareness of life-and-death cycles in nature or an awareness of his own time of life, it is resonant and profound.

Conversely, the city scenes—lush, busy with detail, depicting the moment-to-moment impromptu dance of urban social interaction—seek what is fertile in human nature. The longest series of these concerns a return to the neighborhood of the photographer's youth, Brighton Beach in Brooklyn. While these pictures have an elegiac quality, they are not uncritical, and are sharp-eyed and informative.

Seeing Real Things: through Aug. 24, Smith College Museum of Art, Elm Street, Northampton, (413) 585-2760.