The first thing to be said about “Photography Is Not an Art!” the current exhibition at the Alan Klotz Gallery, is that, of course, photography is an art. The second thing is that Alan Klotz knows this, and he chose his title — as he chose the pictures in the exhibition — to be deliberately provocative. It worked.

None of these photographs were taken for artistic purposes, which Mr. Klotz describes as “the desire to make art with a camera.” He acknowledges that this is one of the traditional reasons for taking pictures, but recognizes three other impulses as well.

There is the topographical impulse, the desire to acquire a scientific rendering of an object for study. There is the documentary impulse, the desire to have an editorial effect as in advertising, photojournalism, and propaganda. And there is the most widely practiced, the vernacular impulse, a “knee-jerk” reaction to a subject — the Grand Canyon, a newborn child, a graduation ceremony — that produces the “snapshot.” It is what people who do not consider themselves photographers take in the billions with their Brownies, their low-end point-and-shoot digitals, their drugstore disposables, and their bleary cell phone cameras.

Mr. Klotz contends that the last three categories inspire and inform the first.

The best known of the topographical pictures in “Photography Is Not an Art!” are three pictures by Harold Edgerton, the MIT engineer who invented the stroboscope, a flash of such short duration and intense illumination it can stop a bullet in flight. Edgerton was very clever at devising ways to show off his invention. In “Cutting the Card Quickly” (1964), the bullet has just torn through a playing card, the jack of diamonds, which is about to collapse. In “Pole Vault” (1964), six successive flashes of the strobe let us study the grace of an athlete as he approaches, rises up, and successfully clears the bar.

Also here are three fascinating pictures titled “Medical Study” (1940s) and attributed to “Anonymous” — the best represented photographer in this exhibition. These are cyanotypes, produced by an early photographic process in which a thin-sliced specimen is placed on sensitive paper and exposed to light: The resulting prints are in attractive shades of electric blue. The subjects here are vertical sections of a human body in profile showing the trunk, spine, chest, and — in one — the skull with its teeth and eye socket.These works have a stylish, art deco cast about them that is quite at odds with their somber content.

Wilson Bentley was obsessed with snowflakes. He was a farmer in Jericho,Vt., who took over 5,000 pictures of snowflakes by placing them on a frozen anvil. There are six of his “Snowflake” pictures in the exhibition, all dated 1885–1931, each, of course, unique.

American space efforts have produced many memorable photographs, some topographical like “The Moon: The Crater of Messier” (1967) — an abstract, somewhat menacing image taken by NASA with its Lunar Orbiter V — and some documentary like “Man on Moon With Flag” (1969). The latter shows the earth as a distant object floating in space, and puts to rest any lingering doubts about Galileo’s cosmology. Decades after it was taken, it still makes us gawk.

Photographer Unknown (probably related to Anonymous) took “Various New Jersey Strikes” (1930s), a series documenting labor confrontations.The pictures are more, not less, dramatic because we do not know the cause or location of the conflicts. They take on a generic quality; restive laborers meet wary law enforcement officers, and politics takes place in the streets.

The six pictures of “Russian Labor Camp” (1950s), by Anonymous himself, are also more powerful because we know so little about them. They were apparently taken with a telephoto lens and blown up so we can see the grainy figures of the soldiers and their German shepherds patrolling the barbed wire and relaxing in the guard towers. The distance the photographer kept from his subject implies how ominous it was.

It should be clear by now that although these pictures were taken without the intentions of high art, many of them are quite affecting. They challenge us to reconsider how we look at a photograph; what we expect to see; what we want to see; and what we think we are seeing. Mr. Klotz maintains that much of the present art market is an “autograph store” where collectors pay more for the fame associated with celebrity artists than for the worth intrinsic to their works. It’s the dose of “art sauce” that gets the big bucks.

To make his point, Mr. Klotz has displayed a selection of 18 3-inch-by-3-inch color prints he rescued in 1971 from the dumpster behind Carhart Photo in Rochester, N.Y. He was getting a degree from the Visual Studies Workshop at the time, and these pictures, edited from over 800 discarded or unclaimed prints that the photofinisher threw away, were offered as his weekly presentation. The class enthusiastically discussed the merits of one picture or the other, the skill they showed, their subtlety and daring. There was considerable unhappiness when Mr. Klotz disclosed the true provenance of the work.

These little photographs — alternately out of focus, under- and overexposed, or lackadaisically framed — are as vernacular as photography gets. They are vacation shots, or images of unidentified people in unspecified situations, but they are not without interest.

In one, a black woman in shorts sits on the lap of a man in a chair. Both their heads are cut off in the framing, so all we see of him is his massive black hand resting possessively on her thigh, an image fraught with sexual innuendo. Three pictures are of naked women, mostly headless, mostly just sad flesh. There is a naked baby in an incubator with prominent red genitals. Animals at the zoo. Cars. The beach. Children in social situations and children blurred beyond recognition. It is life.

But is it art? There are pictures similar to these hanging in prestigious museums with ascriptions to Andy Warhol, William Eggleston, Robert Rauschenberg, and other avant-gardists whose work aspires to the artlessness of the snapshot. Mr. Klotz challenges us to distinguish between Anonymous and the Empyreans.

wmeyers@nysun.com

Until August 19 (511 W. 25th Street, suite 701, between Tenth and Eleventh Avenues, 212-741-4764).