Here is a line you don’t see on too many resumes: “1912: By order of the madams, appointed Official Photographer of Storyville (the red-light district), New Orleans, LA.” But it is possible that you could have seen it on the resume of E. J. “Papa” Bellocq (1873-1949).

From 1898 to 1917, prostitution was legal in Storyville, until the Department of the Navy cracked down, allowing only illegal prostitution to be practiced near military installations. Bellocq, whose clients also included a prominent shipbuilding company and the Catholic Church of New Orleans, was, at least for a time, the photographer of choice for the ladies of the evening. Looking at the 14 photographs and negatives of prostitutes in the exhibition “The Mysterious Monsieur Bellocq,” at the International Center for Photography, it is easy to see why he was so popular.

You may remember Bellocq as the subject of Louis Malle’s rather lackluster film “Pretty Baby” (1978), which starred Keith Carradine, Susan Sarandon, and Brooke Shields. Very little is known about the photographer. A thin biography was culled together, years after Bellocq’s death, from interviews with people who knew him. And only 89 of his glass plates from Storyville – many of which were defaced (possibly by his brother, a Catholic priest) – are extant.

The 8-by-10-inch negatives of prostitutes, originally discovered in 1967 by photographer Lee Friedlander in a New Orleans antique shop, were the subject of a show at the Museum of Modern Art in 1970. Mr. Friedlander made prints from period paper to give them an antique look, but the current exhibition at ICP includes three prints made during Bellocq’s lifetime, possibly by the photographer himself.

Bellocq’s casually seductive images, tastefully hung in simple black frames, are displayed in a low-lit side gallery, which is painted a deep, brothel red. The atmosphere gives the prints a heady, virile backdrop, but does not distract from their rather frank feel as portraits.

There is much speculation about the original purposes of these dreamy pictures, titled here simply as “Untitled (Woman in body stocking)”or “Untitled (Woman standing in underwear)” (all c. 1912). They may have been personal portraits commissioned by the women, sources for artists, or “Blue Book” portraits – images reproduced in the “Yellow Pages” of the Storyville brothels.

They may also have been soft porn. But the pictures – of women, clothed and unclothed, lounging on daybeds or sitting on chairs, occasionally surrounded by photographs, props, or knickknacks (including, in one, a grouping of doll-scale chairs attached with feathers) – are direct, sometimes playful, at best only mildly erotic.

The women, plump and thin, young and closer to middle-aged, have none of the false sexiness or staged, self-consciously coy poses found in much of the erotic photography of the period. Some of Bellocq’s sitters smile naturally. Others lie there totally at ease, almost as if they were hypnotized or asleep.

The beautiful “Untitled (Woman reclining on rattan couch),” is a frontal, hauntingly strange image of a nude who, as if she were levitating above the couch, or wrapped in a cocoon, seemingly floats in the darkness. The picture is almost Egyptian in feel, reminiscent of a Balthusian dream-world.

Both “Untitled (Woman with striped stockings)” (of a seated woman, her head cocked, holding a glass of rye), and “Untitled (Woman reclining with mask)” (of a smiling nude, wearing a Zorro mask, in thigh-high stockings), are as amiable and inviting as they are lightheartedly sexy.

One of the best photos on view is “Untitled (Bellocq’s studio),” which depicts the wall above his roll-top desk. Crowding the desk are female figurines, toy horses, and jockeys, as well as, sitting on the desk or hung on the wall, numerous period photos and prints of women and girls. They include erotic nudes, prim-and proper portraits, idealized children and angels, and neoclassical maidens.

The pictures-within-a-picture gives us the full array of Victorian female stereotypes. Yet, like the portraits of prostitutes, rather than titillate, make us nervous, or stir up feminist ire, the photograph – candid, human, and honest – has the power to disarm. It connects us to ourselves through its glimpse into another time.

Until February 27 (1133 Avenue of the Americans, at 43rd Street, 212-857-0000).