Sweet images flit by, as unremarkable as any home movies of summer vacations your neighbors might twist your arm to see: a young dark-haired woman in a print dress chewing on an apple and coyly lifting a leg for the camera; two men in suits mugging by pretending to box; a ragged woman with scarcely a tooth in her mouth laughing bashfully at the attention she is getting.

Only these amateur movies were, for the most part, shot by American Jews returning to their Polish hometowns in the 1920s and 1930s to visit the kinfolk they had left behind. What makes the images unsettling, even haunting, is that a decade or two later, if the odds bear out, almost all the relatives they filmed would be dead, slaughtered in places like Treblinka and Chelmno, the killing camps of Nazi-occupied Poland. And of course, these subjects, captivated by the novelty of this newfangled gadget — a movie camera — have no premonition of what awaits them.

These home movies, almost six hours in total, have been pieced together and inventively rearranged in montages, triptychs and split screens by the Hungarian documentary filmmaker Peter Forgacs, with an original score by the Klezmatics. His installation, titled “Letters to Afar,” opened Wednesday at the Museum of the City of New York. Visitors to the museum can stroll among the nine screens in a darkened room and glimpse these postcards from a Jewish culture in Poland that is no more.

“It’s Hitchcockian,” Mr. Forgacs said in an interview. “We see everything peaceful and lovely and observe the lives, but we know that every place, every shtetl is a crime scene. And we know most of these people are victims in the Hitchcockian realm. There is suspense. You and I know what happens. They don’t know.”