The current exhibit revisits some of those photos, such as candid and telling pictures of Emperor Haile Selassie of Ethiopia and his nemesis, Benito Mussolini, both shot surreptitiously in train stations (the potato-faced Mussolini is the fellow scratching his nose), and a grainy, sultry image of Josephine Baker, melting into a song.

A wall of photographs shot in Paris faces a wall of images taken in New York. Aigner’s warmth and humor shines through every shot. His photographs lack the exactness of composition of Henri Cartier-Bresson’s and the romantic flair of Robert Doisneau’s, but they are often more intimate, as if Aigner had spent hours chatting with some of his subjects before shooting them. They are driven by spontaneity.

“Dignified Poverty,’’ photographed in Harlem in 1936, portrays an old man standing in a suit and tie, shoes polished. He wears a sign that reads: “Two months waiting for relief. Dispossessed. . . ’’ A younger man, less dignified in costume, sits beside him, dejected. The vintage print “Harlem Beauty Parlor 1936’’ is a close shot of one woman shampooing another’s hair; the viewer might as well be there for a manicure, chatting up the stylist.

Aigner enjoyed antics. The carefree “View From the Empire State Building,’’ made circa 1941, looks down upon sailors taking in the Chrysler Building and beyond, leaning over a concrete railing. In a comic shot, policemen surging through a fenced-in area in the undated “Gendarme, Paris, France’’ look ridiculously stern and forbidding (Aigner’s notes explain that they are policing a soccer game).

There’s a huge archive of Aigner’s photos and papers right here in Allston. It’s a treasure trove the deCordova, and now Gallery Kayafas, have just barely tapped into.