This animated cartoon of a galloping horse is displayed at 12 drawings per second, and the fast motion is on the edge of being objectionably jerky.
35 mm movie projector in operation
Low frame rate video
Simulation of a spinning zoopraxiscope
Video with 4 times increased frame rate
An early projector and seats from a movie theater
1910's 35mm hand-cranked tinplate toy movie projector manufactured by Leonhard Müller in Nuremberg, Germany.
35 mm Kinoton FP30ST movie projector, with parts labeled. (Click thumbnail for larger text.)
Mechanical sequence when image is shown twice and then advanced. 
Outer sprockets rotate continuously while the frame advance sprockets are controlled by the mechanism shown – a Geneva drive.
Imaging lens Diastar of an Askania 35 mm movie projector (focal length: 400 mm)
Christie AW3 platter, BIG SKY Industries console, and Century SA projector
nonrewind in Royal – Malmö, Sweden
A diagram of the VistaVision format
A photo of a 35 mm film print featuring all four audio formats (or "quad track")- from left to right: SDDS (blue area to the left of the sprocket holes), Dolby Digital (grey area between the sprocket holes labelled with the Dolby "Double-D" logo in the middle), analog optical sound (the two white lines to the right of the sprocket holes), and the Datasat time code (the dashed line to the far right.)
Simulated wide screen image with 1.96 to 1 ratio as it would be seen in a camera viewfinder or on a theater screen
Simulated anamorphed image with 1.33 to 1 ratio (4:3) as it would appear on a frame of film

To minimize the perceived flicker, projectors employed dual- and triple-blade shutters, so each frame was displayed two or three times, increasing the flicker rate to 48 or 72 hertz and reducing eye strain.

- Frame rate

A critical part of understanding this visual perception phenomenon is that the eye is not a camera, i.e.: there is no frame rate for the human eye or brain.

- Movie projector
This animated cartoon of a galloping horse is displayed at 12 drawings per second, and the fast motion is on the edge of being objectionably jerky.

1 related topic

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1908 poster advertising Gaumont's sound films. The Chronomégaphone, designed for large halls, employed compressed air to amplify the recorded sound.

Sound film

Motion picture with synchronized sound, or sound technologically coupled to image, as opposed to a silent film.

Motion picture with synchronized sound, or sound technologically coupled to image, as opposed to a silent film.

1908 poster advertising Gaumont's sound films. The Chronomégaphone, designed for large halls, employed compressed air to amplify the recorded sound.
Image from The Dickson Experimental Sound Film (1894 or 1895), produced by W.K.L. Dickson as a test of the early version of the Edison Kinetophone, combining the Kinetoscope and phonograph.
Eric M. C. Tigerstedt (1887–1925) was one of pioneers of sound-on-film technology. Tigerstedt in 1915.
Poster featuring Sarah Bernhardt and giving the names of eighteen other "famous artists" shown in "living visions" at the 1900 Paris Exposition using the Gratioulet-Lioret system.
Newspaper ad for a 1925 presentation of Phonofilm shorts, touting their technological distinction: no phonograph.
Poster for Warner Bros.' Don Juan (1926), the first major motion picture to premiere with a full-length synchronized soundtrack. Audio recording engineer George Groves, the first in Hollywood to hold the job, would supervise sound on Woodstock, 44 years later.
Western Electric engineer E. B. Craft, at left, demonstrating the Vitaphone projection system. A Vitaphone disc had a running time of about 11 minutes, enough to match that of a 1000 ft reel of 35 mm film.
Newspaper ad from a fully equipped theater in Tacoma, Washington, showing The Jazz Singer, on Vitaphone, and a Fox newsreel, on Movietone, together on the same bill.
Dorothy Mackaill and Milton Sills in The Barker, First National's inaugural talkie. The film was released in December 1928, two months after Warner Bros. acquired a controlling interest in the studio.
The Prague-raised star of Blackmail (1929), Anny Ondra, was an industry favorite, but her thick accent became an issue when the film was reshot with sound. Without post-dubbing capacity, her dialogue was simultaneously recorded offscreen by actress Joan Barry. Ondra's British film career was over.
The first Soviet talkie, Putevka v zhizn (The Road to Life; 1931), concerns the issue of homeless youth. As Marcel Carné put it, "in the unforgettable images of this spare and pure story we can discern the effort of an entire nation."
Director Heinosuke Gosho's Madamu to nyobo (The Neighbor's Wife and Mine; 1931), a production of the Shochiku studio, was the first major commercial and critical success of Japanese sound cinema.
Alam Ara premiered March 14, 1931, in Bombay. The first Indian talkie was so popular that "police aid had to be summoned to control the crowds." It was shot with the Tanar single-system camera, which recorded sound directly onto the film.
Show Girl in Hollywood (1930), one of the first sound films about sound filmmaking, depicts microphones dangling from the rafters and multiple cameras shooting simultaneously from soundproofed booths. The poster shows a camera unboothed and unblimped, as it might be when shooting a musical number with a prerecorded soundtrack.
Example of a variable-area sound track—the width of the white area is proportional to the amplitude of the audio signal at each instant.
The unkind cover of Photoplay, December 1929, featuring Norma Talmadge. As movie historian David Thomson puts it, "sound proved the incongruity of [her] salon prettiness and tenement voice."
Premiering February 1, 1929, MGM's The Broadway Melody was the first smash-hit talkie from a studio other than Warner Bros. and the first sound film to win the Academy Award for Best Picture.
Poster for Acabaram-se os otários (1929), performed in Portuguese. The first Brazilian talkie was also the first anywhere in an Iberian language.
Westfront 1918 (1930) was celebrated for its expressive re-creation of battlefield sounds, like the doomful whine of an unseen grenade in flight.
Image of sumo wrestlers from Melodie der Welt (1929), "one of the initial successes of a new art form", in André Bazin's description. "It flung the whole earth onto the screen in a jigsaw of visual images and sounds."

In sound-on-disc technology from the era, a phonograph turntable is connected by a mechanical interlock to a specially modified film projector, allowing for synchronization.

Before sound, 16 frames per second (fps) was the supposed norm, but practice varied widely.