Watching in at least 720p is recommended to appreciate the dark, moody cinematography. Note on 4K:

David Fincher’s Zodiac (2007) is a masterclass in tension, replacing the typical "slasher" tropes of serial killer cinema with a chilling, clinical look at obsession. Spanning decades, the film follows three men—a cartoonist, a reporter, and a detective—as their lives unravel while chasing a ghost who taunts the public with cryptic ciphers.

The film utilizes deep blacks, sickly yellows, and clinical grays to capture the shifting eras from the vibrant 1960s to the drab late 1970s.