It is a 1973 U.S. horror film directed by William Friedkin, adapted from the 1971 novel of the same name by William Peter Blatty, dealing with the demonic possession of a young girl, and her mother’s desperate attempts to win back her daughter through an exorcism conducted by two priests. The film features Ellen Burstyn, Linda Blair, Max von Sydow, Kitty Winn, Lee J. Cobb, Jason Miller, and Mercedes McCambridge. Both the film and novel took inspiration from a documented exorcism in 1949, performed on a fourteen-year-old boy. The film is one of a cycle of 'demonic child' movies produced in the late 1960s and early 1970s, including Rosemary's Baby and The Omen.
AND ON SET INCIDENTS
In 1998, Warner Brothers re-released the digitally remastered DVD of The Exorcist: 25th Anniversary Special Edition. This DVD includes the special feature BBC documentary, The Fear of God: The Making of The Exorcist, highlighting the never-before-seen original non-bloody version of the spider-walk scene. The updated "bloody version" of the spider-walk scene appears in the 2000 re-release of The Exorcist: The Version You've Never Seen utilizing CGI technology to incorporate the special effect of blood pouring from Regan's mouth during this scene’s finale.
The Exorcist was also at the center of controversy due to its alleged use of subliminal imagery. A detailed article in the July / August 1991 issue of Video Watchdog examined the phenomenon, providing still frames identifying several usages of subliminal "flashing" throughout the film. In an interview from the same issue, Friedkin explained, "I saw subliminal cuts in a number of films before I ever put them in The Exorcist, and I thought it was a very effective storytelling device... The subliminal editing in The Exorcist was done for dramatic effect — to create, achieve, and sustain a kind of dreamlike state." However, these quick, scary flashes have been labeled "[not] truly subliminal" and "quasi-" or "semi-subliminal". True subliminal imagery must be, by definition, below the threshold of awareness. In an interview in a 1999 book about the movie, The Exorcist author William Blatty addressed the controversy by explaining that, "There are no subliminal images. If you can see it, it's not subliminal."
It is one of the best horror films that i have never seen, I really recommend it.