The images in the new book, Robert Polidori: After the Flood (Steidl), reiterate the scenes from New Orleans of which we have long grown weary. A car with muddy lines where the flood waters receded, gargantuan swaths of mold along rotting ceilings, house timber strewn like matchsticks.

But the thing that distinguishes Polidori’s photos — 20 of which will be on display at The Metropolitan Museum of Art from Sept. 19 to Dec. 10 — is the thing that is missing from them: people. Instead, the French-Canadian photographer, who once lived in New Orleans’s Gentilly neighborhood, illustrates the lives affected by Hurricane Katrina through the city’s abandoned buildings.

“To me, a house is like an exoskeleton of a person’s life,” Polidori says during a podcast interview with Jeff L. Rosenheim, the Met’s Associate Curator in the Department of Photographs, who also wrote an introductory essay for After the Flood. “These are exoskeletons that have been shed; they’ll never be used again.”

Although Polidori has often been called an architectural photographer, he dodges the classification, instead dubbing himself “more of a sociologist.” To this end, his interior photos from New Orleans were created with very long exposures on 5×7 sheet film, to allow details to come forward in the dim light.

“It starts to render things that are not so readily perceived by the eye right off the bat,” he explains. Then, as if defending himself from the inevitable arguments against photographing horrific events “beautifully,” he adds, “To take a photograph is work, and it should look better than what I saw, or else why do it?”

Polidori has plenty of practice uncovering the obliquely beautiful in scenes of decay. Two of his earlier photo books document Cuba’s crumbling architecture and the town of Pripyat, which has sat deserted since the 1986 Chernobyl disaster.

New Orleans, incidentally, was hardly less dangerous than Chernobyl’s hot zone when Polidori arrived Sept. 20, 2005, his first of four trips to photograph the city. More than two weeks after Katrina hit, 80 percent of New Orleans was still under water, electricity was non-existent, and dangerous molds permeated the putrid, 90-plus-degree air.

“I take images of historical events,” Polidori says, “but that’s only the backdrop for the kind of subject matter that is about psychological loss, pathos, and a kind of paradox.”

In summing up the message of After the Flood for his introductory essay, Rosenheim alludes to these subjects and Polidori’s ability to highlight them through indirect address. Thus Rosenheim also distills his reasons for choosing Polidori’s book as the starting point for the Met’s Katrina memorial exhibition.

“This book makes no attempt to excavate what went wrong in New Orleans or why the state and federal response remains even today predisposed to cronyism, gross fraud, and corruption,” Rosenheim writes. “Instead, it offers tribute and quiet testimony to a city that care forgot.”