TASK: To demonstrate that you fully grasp the concept of frame rates, write a short paragraph explaining the difference between slow motion and frames per second in your ongoing glossary of terms. Cite any web or literature references that you use.
“Frame rate is the engine behind the cinematic lie.”
The amount of time each film frame remains on screen before being replaced by the following image needs to be high enough to create the illusion of movement.
The human brain can perceive between 10 and 12 individual frames every second. Anything faster than this makes our brains blend the frames together into an illusion of movement. This is the basis of animation and is called the ‘Phi Phenomenon’.
The technology available today for cameras and playback allow for very high frame rates and there has been a trend in recent films (3D, CGI) to shoot and play back on frame rates much higher than those needed for the illusion of movement and those used in conventional cinema.
History of frame rates
In the early days of cinema, silent film frame rates varied widely. Cameras and projectors were often hand-cranked. Film strips were projected with a black shutter between each frame and in order for this black flicker of the screen (going dark every second frame) to be undetectable to audiences, each frame was flashed more than once (effectively played back as twos or threes).
Once sound was introduced, a more stable frame rate was required and the established rate became 24 frames per second (that is, each of the 12 frames needed for the Phi Phenomenon displayed twice, on twos). This set frame rate
came to dominate the way all cinema and moving image looked, and still mostly does.
TV: PAL and NTSC
When electronic frame rates came into being with television, problems with flicker and bandwidth were resolved by ‘interlacing’ frames in a comb-like fashion. Each frame would be refreshed at a rate set to the electrical alternating current (AC) of the country. 25fps (PAL) for countries operating on 50 hz AC – Africa, Europe, most of Asia and 30fps for countries operating on 60 hz AC (NTSC) the Americas and Japan.
Digital and CGI
With the introduction of digital media there were less structural reasons to limit what frame rates could be. Filmmakers have tried to push the ‘temporal resolution’ to increase ‘realism’ and decrease motion blur. Tests done on high frame rates such as 60fps were interpreted to produce stronger emotional responses in test audiences and frames as high as 120 fps have been developed (4K) and used in video games and sports broadcasts. Peter Jackson’s CGI
animated and live action hybrid blockbuster The Hobbit (2012) was screened at 48 fps (frames per second), twice that of normal 24 fps speed. Jackson argued that this high frame rate made for a clearer, more ‘real’ film.
It’s a moot point amongst audiences and critics what ‘more real’ means, particularly in the context of CGI. Audience members of The Hobbit complained of headaches and others complained that the ‘high realism’ of the film gave it the look of a ‘made for TV movie’.
It is arguable that the incursion of animated CGI into almost every aspect of commercial narrative film and moving image is beginning to deconstruct the nature of cinema; drawing cinema away from its historically close relationship with literature and pulling it towards the world of computer games both in visual content and structural make up.
Most moving image and cinema are still recorded for playback at 24 fps; a cadence that remains for the time being, something that audiences are more comfortable with.