She learned the intricacies of this dying art from the diminishing band of dye-transfer practitioners. Ms. Curran had to search out the chemical dyes and the coated paper; Kodak stopped manufacturing dye-transfer materials in 1994. She made her own or scavenged from the hoards of fellow devotees.

The use of an obsolescent technique to memorialize “Vertigo” is fitting. Among other things, the movie is about the attempt to hold on to a vanishing past. It is set in a magically beautiful San Francisco that shimmers like a lost dream when we see it today on the screen — a feeling that the filmmaker anticipated. “The things that spell San Francisco to me are disappearing fast,” one character remarks early in the movie.

Ms. Curran said that she considers the dye-transfer process to be the antithesis of the disposable profligacy of digital photography. Because of the extraordinary care Hitchcock took to set up each shot, the act of slowing down to scrutinize surface details starts to seem profound. For instance, by sequencing her stills in the order they appear in the movie, Ms. Curran reveals how Hitchcock used color like a Wagnerian leitmotif, shifting from an early reliance on red, the hue associated with Scottie Ferguson (the character played by James Stewart), to the greens that define the Kim Novak figure, a shop girl named Judy who has been employed by a murderous plotter to impersonate his wife, Madeleine.

In the sumptuous dining room of Ernie’s, the now-gone San Francisco restaurant where Scottie glimpses Madeleine for the first time (and which Hitchcock recreated in the studio), the green of her gown jumps out as a visual exclamation point against red flocked wallpaper. In what may be the most mysterious image in the film, Judy, badgered by Scottie to replicate Madeleine, emerges from her bedroom in a powdery green light cast by the neon hotel sign outside her apartment window. It is a morbid glow; indeed, Scottie’s unrealizable longing will cause Judy’s death.