Sher was born to a Jewish family and raised in Teaneck, New Jersey, where he attended and graduated in 1988 from Teaneck High School. His father, Paul, had been a doctor at New York University Medical Center, while his mother, Joan, was a teacher and taught at the Queens-based Lexington School for the Deaf. It was on a high school-sponsored trip to Paris that Sher first developed a love for photography, after his father convinced him to take a 35mm camera along with him on the trip. Sher has maintained his connections to Teaneck, staying in the basement of his aunt's home there during the filming of Garden State, where he was able to use love of his home state to make location shots there make it appear as what The Record described as a "verdant wonderland". He expressed great pride for his hometown of Teaneck and its diversity, recalling how he "spent a lot of time with an eclectic group of people. There's nothing homogenized about Teaneck even though you're in the middle of suburban New Jersey."