Studio City, California. The first three seasons were filmed on soundstage 19; it then moved to the larger Stage 9 for the remainder of its production. Despite numerous establishing shots taken in New York City, all scenes of the actors walking in New York were also filmed at CBS Studio Center, on their New York Street backlot. Other locations on the CBS lot were also used, as well as scenes filmed at Paramount Studios and Warner Brothers Studios Hollywood. A source of problems for the cast was the small sets, especially that of Jerry's apartment; Alexander noted "If you knew you were doing a series for nine years, you would never build that set". Adding to the problem was that the scripts contained only minimal physical direction, leaving the actors struggling to come up with actions to perform while speaking. Eventually, they got into a routine of directing each other on how to make their movements look natural. Alexander said this helped them build chemistry with each other. Filming usually went long, as the cast and David were perfectionists. If a joke didn't elicit the reaction they hoped for, they rewrote it and performed it again. In at least one case, "The Marine Biologist", this led to David writing an entirely new scene requiring Alexander to memorize a monologue in only a matter of minutes. Laugh tracks were used only for matching shots, not for artificially adding laughter. Various locations used for establishing shots included Tom’s Restaurant at 112th Street and Broadway (Monk’s Cafe), Midtown West’s Roosevelt Hospital (recurring exterior emergency room scene, and indoor scenes in 'The Junior Mint' and 'The Bris'), 22 37th Street, Queens (The Costanza’s house), the Taconic State Parkway exit to the Hopewell Junction, Dutchess County, New York (driving scene in 'The Bubble Boy'), Sunrise Highway at Wading River Road, Center Moriches, Long Island (driving scene in 'The Hamptons'), and the Amagansett farmers market, Long Island ('The Hamptons'). The exterior shot used for Jerry’s New York apartment building was actually located at 757 New Hampshire Avenue, Los Angeles. The live stand-up comedy performed by Seinfeld at the beginning of most episodes was truly filmed at The Improv, a comedy club at 358 West 44th Street, Manhattan; though it closed in 1993, a new comedy club still operates at this site today. High-definition versions There are two high-definition versions of Seinfeld. The first is that of