Blow-Up (1966)

A successful mod photographer in London whose world is bounded by fashion, pop music, marijuana, and easy sex, feels his life is boring and despairing. But in the course of a single day he accidentally captures on film the commission of a murder. The fact that he has photographed a murder does not occur to him until he studies and then blows up his negatives, uncovering details, blowing up smaller and smaller elements, and finally putting the puzzle together.