Editing Back to the Future (section)

===Filming with Fox===
[[File:Court house from Back to the Future films.jpg|thumb|left|alt=the courthouse with its clock tower|The Hill Valley town square and clock tower were a set built on the [[Universal Studios Hollywood|Universal Studios]]' [[backlot]].]]
Fox's first day on set was January{{spaces}}15, 1985.{{sfn|Gaines|2015|pp=41, 43–44}} He filmed ''Family Ties'' during the day before traveling to the ''Back to the Future'' filming location. Often, he would not return home until early the following morning, and on weekends, the schedule was pushed back further as ''Family Ties'' was filmed in front of a live audience.<ref name="EsquireDidntGetMade"/><ref name="TheGuardianHowWeMade"/><ref name="NYTimesFoxInterview"/> The [[teamster]] drivers entrusted with dropping off Fox at home often had to carry the actor to bed.<ref name="EsquireDidntGetMade"/> This continued until April, when ''Family Ties'' finished filming.{{sfn|Gaines|2015|pp=103–104}} Gale said Fox's youth meant he could cope with less sleep than usual;<ref name="TheGuardianHowWeMade"/> Fox described it as exhausting, but worth the effort.<ref name="NYTimesFoxInterview"/> Further into the filming schedule, Fox was energetic during his scenes but struggled to stay awake off set. He ad-libbed some lines when he forgot the intended dialogue,<ref name="TheGuardianHowWeMade"/>{{sfn|Gaines|2015|p=114}} and recalled looking for a camcorder on the ''Family Ties'' set, before realizing it was a prop on ''Back to the Future''.{{sfn|Gaines|2015|p=114}} He also had to learn to mimic playing the guitar and choreographed skateboarding routines taught by [[Per Welinder]] and Bob Schmelzer.<ref name="CBRSkateboard"/>

To compensate for his conflicting schedules and reduce production costs, some scenes involving Marty were shot without Fox, who filmed his part separately.<ref name="HFPAOralHistory"/><ref name="TheGuardianHowWeMade"/> Re-shooting scenes allowed the filmmakers to identify problems and implement new ideas. To avoid building an additional classroom set, the opening pan across the array of clocks in Doc Brown's laboratory replaced an opening scene where Marty sets off a fire alarm to get out of detention.<ref name="ColliderDifferences2020"/>{{sfn|Gaines|2015|p=50}} The height differences between Stoltz and Fox necessitated other changes, such as a scene of Fox teaching George how to punch because Fox could not reach the necessary prop.{{sfn|Gaines|2015|p=51}} According to Gale, once Fox replaced Stoltz, the atmosphere on set improved.<ref name="EsquireDidntGetMade"/> Thompson anecdotally said while Stoltz ate lunch alone in his trailer, Fox ate lunch with the cast and crew.{{sfn|Gaines|2015|p=47}}

The production used many locations in and around [[Los Angeles]]. The [[Courthouse Square|clock tower]] is a structure on the [[Universal Studios Lot]] in [[Universal City, California]].<ref name="ClockTower" /><ref name="Curbed" /> When filmed from below, Lloyd was positioned on a recreation of the clock tower, but when filmed from above, Lloyd stood atop the tower itself.{{sfn|Pourroy|1985|p=64}} Production designer [[Lawrence&nbsp;G. Paull]] insisted on using the Universal backlot sets because of the difficulties and costs involved in making an on-location area look 1955-appropriate.{{sfn|Gaines|2015|p=143}} [[Whittier High School]] in the city of [[Whittier, California|Whittier]] is the Hill Valley high school. Marty's home and the surrounding Lyon estates are in [[Arleta, Los Angeles]]. Several of the residential locations were filmed in Pasadena: Lorraine's and George's 1955 homes, and Doc Brown's 1955 home. (Its exterior is the [[Gamble House (Pasadena, California)|Gamble House]]; interiors were shot at the historic [[Blacker House]].)<ref name="Curbed"/> [[Puente Hills Mall]] in [[City of Industry, California]] serves as the Twin Pines mall, which later becomes the Lone Pine mall after Marty knocks over one of the trees at Twin Pines ranch in 1955, which was filmed at the Walt Disney Studios-owned [[Golden Oak Ranch]] in [[Newhall, Santa Clarita, California]].<ref name="VultureStoltz" /><ref name="Curbed" /> Other locations include the basement of the [[Hollywood United Methodist Church]] where the school dance was filmed, and [[Griffith Park]], where Marty begins his drive to the courthouse to return to 1985, passing by a lamp post outside the [[Greek Theatre (Los Angeles)|Greek Theatre]].<ref name="Curbed" />

Filming [[Wrap (filmmaking)|concluded]] after 107 days on April{{spaces}}26, 1985. The final day of filming included [[Pick-up (filmmaking)|pick-up]] shots of Marty and Einstein the dog in the DeLorean.{{sfn|Gaines|2015|pp=103–104}}