Slow Motion Frame Rate Calculator

Slow motion is produced by sampling time more densely than it is replayed. The capture rate equals the timeline playback rate multiplied by the desired slowdown, so 4x slow motion on a 24 fps timeline requires 96 fps and 8x requires 192 fps, while 120 fps footage placed on a 30 fps timeline yields exactly 4x. Duration scales by the same factor: a 2 second capture at 8x occupies 16 seconds of screen time, which is why most slow motion shots in finished work run only 3 to 8 seconds of playback and represent well under a second of real action. Frame interval shrinks correspondingly, from 41.7 ms at 24 fps to 8.33 ms at 120 fps and 1.04 ms at 960 fps. The binding constraint in practice is light. The 180 degree shutter convention sets exposure time at half the frame period, meaning 1/48 s at 24 fps but 1/240 s at 120 fps, a reduction of roughly 2.3 stops that must be recovered through aperture, sensitivity or added illumination. Continuous sources are required because any flicker in mains-powered lighting that is invisible at 24 fps becomes a pulsing exposure at several hundred frames per second. Sensor readout imposes a second limit: many cameras drop from full resolution to 1080p or 720p above 120 fps because the pipeline cannot sustain the data rate, and rolling shutter skew depends on line readout time rather than nominal frame rate. Storage scales in direct proportion to capture rate, so a 4x capture consumes four times the data per second of real time recorded.

Slow motion predates electronic imaging. The Austrian priest and physicist August Musger developed and patented a slow-motion projection method in the first decade of the twentieth century, coining the German term Zeitlupe, literally time magnifier, which is still the standard word for the effect in German-speaking countries. In the hand-cranked era the technique was described as overcranking, running the camera faster than the projection speed, with undercranking used for the accelerated chases and pratfalls of early comedy. The vocabulary survived the disappearance of the crank and remains standard on professional sets. Scientific and military work drove capture rates far beyond cinema needs. Rotating mirror and rotating prism cameras developed through the 1930s and 1940s allowed ballistics, detonation and impact studies at rates film transport alone could never reach, and companies such as Photo-Sonics supplied specialized high-speed film cameras to aerospace and weapons programs for decades. Digital high-speed imaging matured with Vision Research's Phantom line from the 1990s, which made thousands of frames per second available with immediate playback rather than laboratory film processing. High frame rate capture reached consumers rapidly in the following decade, with the Casio EX-F1 offering 1200 fps at reduced resolution in 2008, smartphone 240 fps modes appearing around 2014, and 960 fps burst modes shipping in flagship phones by 2017.