When Robert Neville sees the mannequin he calls Fred outside on the street, it looks like the mannequin moves its head a little. During that scene, a mime replaced the mannequin to try and play with people's minds when they watched that scene.
When he was in pre-production on this film, director Francis Lawrence found himself watching The Pianist (2002) with the sound off in order to not disturb his sleeping baby, and he found the quiet effect was extremely moving. He then made stark silence, with limited ambient effects or musical cues, a major part of this film's process.
Warner Bros. initially opposed filming in New York City, because of the costs and logistical challenges. However, Michael Tadross, a veteran New York City production manager, got the city to approve closing the Grand Central viaduct, several blocks of Fifth Avenue and Washington Square Park, albeit at night and on weekends, between September 2006 and April 2007.
While doing a press conference in Japan for the release of the movie, Will Smith accidentally revealed the ending to a collection of entertainment reporters. Warner Bros. asked the reporters and all those present to withhold the ending, and the reporters all obliged without any pay-off or consideration.
The studio spent an estimated five million dollars for a six-night shoot in New York City, involving the Brooklyn Bridge. To film in this location, the producers needed the approval of as many as fourteen government agencies. The shooting required a crew of 250, plus 1,000 extras, including 160 National Guard troops in full combat gear.
While shooting under the Brooklyn Bridge at the end of January, it got as cold as seven degrees Fahrenheit. To boost everyone's spirits one night, Will Smith came out and sang his hit song "Summertime" (1991).
In one scene in the deserted street, a billboard can be seen with a large Batman and Superman logo superimposed over each other, and the date "5-15-10." This is an in-joke at the expense of screenwriter Akiva Goldsman. Goldsman did script rewrites for a "Batman Versus Superman" project in 2002. This was just one of the countless attempts to revive the Superman franchise that culminated in the release of Superman Returns (2006). It would not be until 2016 that Superman and Batman would share the silver screen together in Batman v Superman: Dawn of Justice (2016). Will Smith later played Deadshot in Suicide Squad (2016), which takes place in the DC Extended Universe of Batman v Superman: Dawn of Justice (2016).
At the New York premiere, Will Smith apologized for the disruption shooting of the movie had caused to the city residents. He said, "I would like to issue a public apology to the citizens of New York. There were a couple of streets we had to close off during the filming of I Am Legend (2007). I am very sorry. People were kind of upset with me."
Much of this film was shot on location in New York City's Washington Square Park, during fall and winter 2006-2007, causing holiday decorations to be taken down, and replaced tumultuously for over three months.
The noise from the special effects explosions, used in the scenes along the East River, interrupted voice recording on the Nickelodeon children's show Wonder Pets! (2005), which had its production offices one block from where the shooting of I Am Legend (2007) took place.
The filmmakers couldn't close all the streets at once, so each weekend, they'd film Will Smith driving on a different corner. People on the street hid, and took cellphone videos of Smith, as he drove by.
According to Akiva Goldsman, there were plans to produce a follow-up film, with scripts even being written around a prequel and sequel. One prequel involved the outbreak occurring during the Thanksgiving Day parade in New York City, while another focused on the human population becoming low. The latter prequel featured a trip to Washington, D.C., and an infected elephant escaping from the zoo. However, the project was effectively shelved.
In the film, Will Smith's character holds up a CD, calling it "the best album ever made." The album is Bob Marley's "Legend," which is a greatest hits compilation that was released after Marley's death.
When Neville brings Sam back to his lab and gently sets the dog on the operating table, nearby trainers cued the dog to "play dead" and keep her head down. The actor was well-rehearsed in handling the dog. For a shot when Sam tries to bite Neville, a chew toy was placed near the actor's shirt and the dog was cued to "get it." The toy and the trainer were in the scene but removed in post-production. The syringe he uses was a retractable prop and the dog was never injected. The dog's red eyes and veins were a digital effect.
Before it was finally green-lit with Will Smith as the lead, and Francis Lawrence directing, the closest the project came to being made was in early 1998, when Warner Bros. gave an initial "OK" for a version starring Arnold Schwarzenegger, with Ridley Scott directing. The studio's art direction and special effects workers had even begun working on a design for the apocalyptic mutant creatures. However, some high-profile big-budget failures for Warner Bros., and the huge (for that time) initial budget of 125 million dollars, led to the project being put into turnaround. If the film had been made from Mark Protosevich's original screenplay, it would have differed from the 2007 version in three major ways: it was to be set in the Bay Area of California, it would have been more of an action film, and less of a drama, and it would have been filmed with the intent of being R-rated, which would have possibly drawn in fewer viewers.
In the book by Richard Matheson, people who died of the disease return to life as vampires, retaining their human appearance. Like traditional vampires, they dislike garlic and mirrors, hunt the living, and die from a stake through the heart.
Foreshadowing: Neville captures an infected female with a snare trap, and the Alpha of the pack leaves the dark to glare at Neville before walking back into the dark. Neville takes it as a sign that they've lost their self-preservation skills. The Alpha later shows up, having caught Neville in the exact same type of snare trap he built with a pack of dogs, hinting that the infected are intelligent, and that the Alpha wants the girl back.
The original plan was to have the infected people be played by real people wearing extensive make-up and prostetics, but the first tests results made them look more like "angry mimes," according to the crew. The choice was then made to use computer generated imagery (CGI) to depict the creatures instead.
In the beginning, while the Doctor is being interviewed about the cure for cancer, there is a news ticker at the bottom of the screen with the headline, "Shaquille O'Neal to announce his retirement at the end of 2010 season."
Warner Bros. gained the rights to the novel by Richard Matheson in the 1970s and produced a version of it, called The Omega Man (1971), in 1971. Previous to that, Associated Producers did an adaptation in 1964 called The Last Man on Earth (1964) with Vincent Price, shot in Italy and directed by Italian Ubaldo Ragona and American Sidney Salkow. Although Matheson did not contribute to the screenplay of the 1964 film, which took a critical drubbing, he did contribute to the screenplay for this film.
When Sam runs on a treadmill, the dog was well-rehearsed to run on the treadmill. Trainers got her accustomed to a slow walk and gradually worked their way to a run. The dog was attached to a safety rope held by a trainer, but she was so comfortable with the action that the trainer never needed to use it. The dog was rewarded with treats.
When Neville gives Sam a bath. The dog was accustomed to getting baths and the water was comfortably warm. The shampoo was a no-tears formula and a traction mat lined the bottom of the tub. The dog was given treats and was thoroughly rinsed and dried between takes.
In flashback scenes, Sam is seen as a puppy. For these scenes, trainers instructed the actors on how to perform the mild action, mostly holding the puppy in their arms or laps. The scene with the puppy in the moving vehicle was filmed on an indoor stage against a green screen, and a trainer was hiding in the backseat. The vehicle never actually moved; crew members rocked the vehicle to make it appear to move, and the moving background was added in later. The puppy was accustomed to being held and was unfazed by helicopter noises. Between takes, she was placed in a heated blanket to keep her warm and relaxed. The helicopter explosion was computer-generated imagery (CGI).
Sam is on the wing of an aircraft while Neville drives golf balls. This scene was filmed on an actual airplane with especially large wings. The trainer walked the dog up custom-made stairs and put her in a "down/stay" position on a platform with special traction on top of the wing. The trainer hid in a nearby box where he maintained the dog's eye contact and cued it to stay. Several trainers surrounded the area as a precaution. The trainer walked the dog down the stairs immediately after filming.
When Sam is seen in a moving vehicle, a foam mat covered the car seat for traction, and the dog was tethered to the seat with a waist tie, which was held by a trainer hiding in the backseat. The backseat trainer gave the dog commands, and a trainer just outside the car door occasionally held food out to get the dog to stick her head out. A stunt car was used for the part of the scene in which Neville drives erratically. High-speed chases were filmed in separate shots without the dog -- she was never actually in a high-speed chase or jolted around in a sudden stop. For shots in which the car spins around, crew members propped the special car up onto rotating dollies and manually spun it for the short take. The dog, who seemed to enjoy the movement, was secured in the car and held by the trainer. For scenes in which the car simply drives down the street, the actor drove slowly and the dog was secured by a waist line attached to a harness and leash held by a backseat trainer.
It is highly plausible that, within the story, the timecoded copies of the NBC Today show, and anything else he would have watched on broadcast television, would have been taken from the NBC base at 30 Rockefeller Plaza (a.k.a. 30 Rock).
The rifle used by Will Smith throughout the movie is a Colt Law Enforcement Model 6920 Carbine with a Trijicon ACOG optic (TA31 series), C-MORE free floating rail, ERGO rail covers, and Pentagon MD3R tactical light. According to the Propstore of London, the weapon was modified to fire fully automatic for the film, he also uses a Heckler & Koch Mark 23 with a flat earth (tan) frame as his main sidearm. He is seen with it holstered, but also carries one in the driver's door, most notably to shooting the infected dogs in the middle of the film. There were several identical firing Mark 23s used on-set, as well as rubber versions for stunt work. For most scenes where Will Smith carried the weapon in the holster, a lightweight airsoft Mark 23 (with frame painted tan to match the firing pistols) was used, and a Beretta 92FS, and a Smith & Wesson 5946. The 5946 in the DAO setting is one of three pistols used by the NYPD (the other two being the Glock 19 and the P226 DAO), so it was likely recovered by Neville from an NYPD precinct.
Will Smith and Charlie Tahan have both worked in DC related material; Smith played Floyd Lawton aka Deadshot in Suicide Squad (2016) and Tahan played a young Jonathan Crane aka The Scarecrow on Gotham (2014-2019).
The film that Ethan watches is Shrek (2001). Eddie Murphy whom provided the voice of Donkey in that movie had starred opposite Will Smith's wife Jada Pinkett Smith in The Nutty Professor (1996), the same year Will did Independence Day (1996).
The trivia items below may give away important plot points.
There is an alternate ending of the film where Robert Neville (Will Smith) not only survives, but also learns a very valuable lesson. When the monsters are attacking them, the leader stops and then makes a butterfly with his dirty hands on the window. Smith's character then sees a butterfly tattoo on the infected woman that he kidnapped to experiment on. He reunites her with the monsters and the leader passionately rubs heads with her and lets out a very pained roar while crying. Neville learns that the monsters may not be human, but have still retained some human emotions and higher brain functions. He tearfully apologies to the leader, who then orders the rest of the infected people to leave them. Neville then breaks down, sitting and looking at the pictures of earlier test subjects that died during his experiments. He then abandons his research and leaves by car, together with Anna and Ethan, and the vial of blood containing the cure. This idea was completely edited out of the film and a new ending put in, where Neville gives the cure to Anna. He then saves her and Ethan by blowing himself and the monsters up with a grenade. Anna and Ethan subsequently leave for Vermont and find the colony. Many people hated this ending, so a version with the alternate ending was released on limited edition DVD sets & the Blu-Ray version. Many people prefer the alternate ending over the theatrical ending, believing it gives the plot a moral and more meaning to the film's title by having Neville doing something "legendary".
In the last scene of the theatrical version, Anna and Ethan are driving through the autumn countryside. This scene was filmed in West Amwell, New Jersey, because in the original filming location, the leaves on the trees had already fallen off.
During the scene where Neville is searching the apartments, there is an article posted on one of the cabinets stating that infected dogs could come out at dusk, leading to a later scene where Neville and Sam are attacked by dogs. This explains why the Alpha does not also attack Neville as the sun had not completely gone down.
In Times Square, there is a billboard for the Justice League: Mortal movie set to open May 10, 2010. Also in the video store, posters for the live action adaptations of Teen Titans and Green Lantern (2011).
There are references to butterflies scattered throughout the movie: the "God Still Loves Us" poster; when Neville was talking to Sam about the mannequin he met in the video store, a butterfly is shown flying near Sam's face for about a second; at the ending, the Dark Seeker makes cracks in the glass that represent a butterfly; Neville hearing "Daddy, its a butterfly!" (a quote from his dead daughter); Anna has a butterfly tattoo on her neck.
All vehicles driven by the main characters are Fords. There is the Ford/Shelby GT500 Mustang that Neville drives in the beginning, the Ford Expedition he drives throughout the film, and the Ford Escape used to depart New York City at the end.