Billing Displacement: Jamie Lee Curtis is billed second, yet is arguably the least important of the protagonists. Nick would probably be second after Stevie in terms of prominence, but Tom Atkins is billed fifth.
California Doubling: The sequence of Mr Machen telling the ghost story was shot on a sound stage; the only scene in the film not done on location.
Contractual Obligation Project: Avco Embassy offered John Carpenter a two-picture deal after the success of Halloween, and The Fog was the first one (figuring that producing another horror film was a wise move). The second was Escape from New York.
John Carpenter didn't think much of the film at the time, but he warmed to it eventually. He also felt he was so bad in his cameo as Bennett that he stopped acting in his movies afterwards (except for "helicopter pilots and walk-ons").
Jamie Lee Curtis expressed surprise at how many fans it has, because "I don't think it's that good a film".
Hostility on the Set: A mild example. John Carpenter and Debra Hill had split up previously, and he was now dating Adrienne Barbeau. Jamie Lee Curtis, who had become close friends with both and took their break-up especially hard, has said that it was "very hard" for Debra to work with her ex-boyfriend and his new partner.
Inspiration for the Work: John Carpenter stated that the inspiration for the story was partly drawn from The Crawling Eye. He has also said that he was inspired by a visit to Stonehenge with his co-writer/producer (and then-girlfriend), Debra Hill. While in England promoting Assault on Precinct 13 (1976), Carpenter and Hill visited the site in the late afternoon one day and saw an eerie fog in the distance. In the DVD Commentary, Carpenter noted that the story of the deliberate wreckage of a ship and its subsequent plundering was based on an actual event that took place in the 19th century near Goleta, California (this event was portrayed more directly in the 1975 Tom Laughlin film, The Master Gunfighter). The premise also bears strong resemblances to the John Greenleaf Whittier poem The Wreck of the Palatine which appeared in The Atlantic Monthly in 1867, about the wreck of the ship Princess Augusta in 1738, at Block Island, within Rhode Island.
No Budget: Just about $1 million to make. Apparently the advertising budget was three times that.
Playing Against Type: All three returning cast members from Halloween invert their usual personas.
Jamie Lee Curtis had played the shy, bookish Laurie Strode, who is anxious about even a boy knowing she likes him. Elizabeth is a more rebellious rich girl who hitchhikes across the country and hops into bed with a man she just met. She commented on how Elizabeth felt a little closer to her own personality, and her wardrobe was more contemporary.
Charles Cyphers had played the responsible and strait-laced Sheriff Brackett. Dan O'Bannon is the goofy meteorologist who slacks off work to flirt with a radio host. He also proves ineffective in a confrontation and is killed off.
Nancy Loomis had played the rebellious, ball-busting Annie Brackett - who slacks off her babysitting duties to fool around with her boyfriend. Sandy is Mrs Williams's Hypercompetent Sidekick and, while she has a snarky side, she's far more caring and sensible. She also survives the final confrontation.
Three cast members from Halloween return - Jamie Lee Curtis, Charles Cyphers and Nancy Loomis. Many of the same crew from Halloween reunited as well - producer Debra Hill, cinematographer Dean Cundey, and editors Tommy Lee Wallace and Charles Bornstein. Adrienne Barbeau had been directed by John Carpenter in the Made-for-TV MovieSomeone's Watching Me!
Real Life Writes the Hairstyle: The re-shot scenes (see below) are easy to spot because Elizabeth's hair drastically changes in length.
Reality Subtext: Janet Leigh admitted to being afraid of Hal Holbrook in their scenes together. She found his line readings so chilling that Kathy William's reactions to the diary were genuine.
Kathy Williams was offered to Janet Leigh because John Carpenter was a huge fan of her work in Vikings, and Debra Hill idolised her from Psycho.
Debra Hill also said that John Houseman's appearance gave the film a sense of legitimacy, and he was given significant billing in the promotional materials.
Throw It In!: As Janet Leigh stands outside the church door, what looks like an arc of fog can be seen above her. This was an accidental fog on the top of the lens that they decided to leave in.
Tuckerization: Many characters are named after various friends and colleagues of John Carpenter. Nick's last name is Castle, after the actor who played Michael Myers in Halloween (1978), Dan O'Bannon is the screenwriter of Dark Star (which he later "remade" as Alien), Tommy Wallace is an art director, sound designer and editor he worked with frequently (also has the two-fer of being the same names as the children in Halloween - Tommy Doyle and Lindsey Wallace), and Mrs Kobritz's last name comes from Richard Kobritz - who produced a Made-for-TV MovieSomeone's Watching Me! that he directed.
The role of Father Malone was offered to Christopher Lee, but he couldn't make it. A role was also offered to Kurt Russell.
The original cut of the movie was only 80 minutes and, according to Carpenter, pretty boring. To pad things out for a theatrical release and make it more exciting, he had several new scenes added in reshoots. Among those includes the opening scene with John Houseman telling the ghost story. Likewise, the scene of Nick telling Elizabeth a story below deck on the ship before they find Tommy's body was written in to replace "a scare that didn't work".
The lead ghost Blake was played by make-up specialist Rob Bottin. He applied to work on the film in a special effects capacity. But John Carpenter took note of his large build and cast him as Blake.
The ghosts were barely seen in the original version of the attack on the boat. The re-shot version made it more violent. Additionally, the fight between Stevie and the ghosts on the lighthouse roof was padded out to be more suspenseful - including her getting a hook in the shoulder. This explains why she appears unaffected by the wound later.
Before the remake came along, John Carpenter said he was interested in producing an anthology series of films - not featuring the same characters or places, but featuring the fog as a catalyst for other supernatural events. As the series progressed, connections to the first film would have become more apparent.
