<P> Frame rate (expressed in frames per second or fps) is the frequency (rate) at which consecutive images called frames appear on a display . The term applies equally to film and video cameras, computer graphics, and motion capture systems . Frame rate may also be called the frame frequency, and be expressed in hertz . </P> <P> The temporal sensitivity and resolution of human vision varies depending on the type and characteristics of visual stimulus, and it differs between individuals . The human visual system can process 10 to 12 images per second and perceive them individually, while higher rates are perceived as motion . Modulated light (such as a computer display) is perceived as stable by the majority of participants in studies when the rate is higher than 50 Hz through 90 Hz . This perception of modulated light as steady is known as the flicker fusion threshold . However, when the modulated light is non-uniform and contains an image, the flicker fusion threshold can be much higher, in the hundreds of hertz . With regard to image recognition, people have been found to recognize a specific image in an unbroken series of different images, each of which lasts as little as 13 milliseconds . Persistence of vision sometimes accounts for very short single - millisecond visual stimulus having a perceived duration of between 100 ms and 400 ms . Multiple stimuli that are very short are sometimes perceived as a single stimulus, such as a 10 ms green flash of light immediately followed by a 10 ms red flash of light perceived as a single yellow flash of light . </P> <P> Early silent films had stated frame rates anywhere from 16 to 24 frames per second (fps), but since the cameras were hand - cranked, the rate often changed during the scene to fit the mood . Projectionists could also change the frame rate in the theater by adjusting a rheostat controlling the voltage powering the film - carrying mechanism in the projector . Film companies often intended that theaters show their silent films at higher frame rates than they were filmed at . These frame rates were enough for the sense of motion, but it was perceived as jerky motion . 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 . Thomas Edison said that 46 frames per second was the minimum needed for the eye to perceive motion: "Anything less will strain the eye ." In the mid to late 1920s, the frame rate for silent films increased to between 20 and 26 fps . </P>

What is the fps limit of the human eye
find me the text answering this question