Correction Appended| There are about a half a million images in the photography collection on the third floor of the main branch of the New York Public Library on Fifth Avenue. The collection’s curator, Stephen Pinson, spent a year searching through those photographs for 20th-century portraits, and now there is a handsome exhibition, “Recollection ,” in the library’s Print and Stokes Galleries. On display are portraits from more than 90 photographers of the 20th century, including Richard Avedon, Diane Arbus, Duane Michals, Henri Cartier-Bresson, August Sander and William Wegman.

The library’s collection has iconic images, as well as many powerful photographs that are little known. “One of the pleasures of having a collection that is a half-million photographs,” Mr. Pinson said, “is that even though I’ve been here now six years, there are things I still haven’t seen with my own eyes.”

In his search, Mr. Pinson found a print of André Kertész’s portrait of the artist Tsuguharu Foujita (Slide 3). The bottom left corner of the image is missing. “I had not actually seen this particular image by Kertész at all,” Mr. Pinson said. “We could have repaired it, but I would rather have it show its signs of history than add a fake corner onto the photograph. So we left it that way, framed it that way, and it’s still that way on the online exhibition as well.”

The only previous show of the library’s collection took place in 1981, shortly after the creation of the library’s photography division. Mr. Pinson wanted to focus on 20th-century work to differentiate the current exhibition from the first, which focused on 19th-century images. The show runs through Jan. 2. Most of the images can be viewed online, along with a music video of the images.

CORRECTION

An earlier version of this post included incorrect information provided by the New York Public Library. The portrait by Andrez Kertész (Slide 3) is of the artist Tsuguharu Foujita, not the sculptor and designer Isamu Noguchi. The post and the slide have been updated with the correct identification.