Heard of 24P? Ever wondered what it was? Essentially, it’s a technology that allows video to look more like film. Cinematic film is run at 24 frames per second (fps), essentially 24 single images pass through the camera (or projector) every second. The perceptual process of the brain holds these individual images on the retina causing the perception of smooth motion.

Video, however, uses a different frame rate; in the U.S. it is 29.97 interlaced frames per second (fps) – commonly rounded to 30fps. Each frame of video is made up of 60 (again rounded up from 59.94) individual fields, odd and even.

Odd numbered fields consist of half the image in odd scanlines and even fields hold the other half of the image in even scanlines. Even and odd fields are interlaced together to comprise a frame. Traditional television sets show interlaced videos in fields like this, the soft comforting flicker of television is one we’ve grown quite accustomed to and generally don’t even notice.

Non-interlaced video is called progressive scan where the entire frame is shown at once.

Progressive scan is abbreviated p and interlaced i; the various formats are noted with their frame rate followed by the scan abbreviation (e.g. 24p, 30p, 60i). You’ll also find these p and i notations used for describing HDTV (e.g. 1080i, 720p). In these cases the number value stands for the number of lines of vertical resolution and not the frame rate.

The advantage of using 24p is to achieve a more cinematic and aesthetically pleasing look for video. As opposed to having the traditional, flat and high contrast appearance of video, 24p allows filmmakers and others interested in achieving a film-look to do so much less expensively than actually shooting on film.

Questions or comments? Contact Leslye at leslye@reflectiondigital.com