in, the screen goes dark. Although the movies are
distinguished from other arts by their dependence
on light and movement, we spend a good amount of
our time in movie theaters sitting in complete dark-
ness, facing a screen with nothing projected on it
at all!
The movement we see on the movie screen is an
illusion, made possible by two interacting optical
and perceptual phenomena: persistence of vision
and the phi phenomenon. Persistence of visionis
the process by which the human brain retains an
image for a fraction of a second longer than the eye
records it. You can observe this phenomenon by
quickly switching a light on and then off in a dark
room. Doing this, you should see an afterimage of
the objects in the room, or at least of whatever you
were looking at directly when you switched the
light on. Similarly, in the movie theater we see a
smooth flow of images and not the darkness
between frames. Thus, the persistence of vision
gives the illusion of succession, or one image follow-
ing another without interruption. However, we
must also experience the illusion of movement, or
figures and objects within the image changing posi-
tion simultaneously without actually moving.
The phi phenomenonis the illusion of move-
ment created by events that succeed each other
rapidly, as when two adjacent lights flash on and off
alternately and we seem to see a single light shift-
ing back and forth. The phi phenomenon is related
to critical flicker fusion, which occurs when a sin-
gle light flickers on and off with such speed that the
individual pulses of light fuse together to give the
illusion of continuous light. (Early movies were
called flicksbecause the projectors that were used
often ran at slower speeds than were necessary to
sustain this illusion; the result was not continuous
light, but a flickering image on-screen. The most
acute human eye can discern no more than fifty
pulses of light per second. Because the shutters of
modern projectors “double-flash” each frame of
film, we watch forty-eight pulses per second, close
enough to the limit of perception to eliminate our
awareness of the flicker effect.) The movie projec-
tor relies on such phenomena to trick us into per-
ceiving separate images as one continuous image;
and because each successive image differs only
slightly from the one that precedes it, we perceive
apparent motionrather than a series of jerky
movements.
The most dazzling contemporary films, such as
Andy and Lana Wachowski’s The Matrix(1999),
exploit these properties of cinematic movement to
create kinetic excitement that makes the impossi-
ble look totally possible. How do they do this? Spe-
cial effects, involving the most advanced computer
technology in both hardware and software, play a
large role in creating this virtual reality. Indeed,
seamlessly integrated to create the film’s virtual
realm, special effects reportedly constitute 20 per-
cent of The Matrix. But such sophisticated effects
would not be possible without the simple illusions
just discussed. Much of what we regard as the
absolute cutting edge of moviemaking technology
capitalizes on these illusions, especially the speed-
ing up or slowing down of movement to achieve the
desired effects.
In making The Matrix, the filmmakers initially
discovered that a number of the necessary action
sequences might not be possible, because they
required motion to be captured at exceptionally
high speeds. That is, to create the illusion of such
slow motion, the camera would have had to speed
up beyond its capacity. Working with engineers, the
filmmakers developed new technology in a process
that resembled sequence photography experiments
from the earliest days of motion-picture photo -
graphy. For example, a scene in which Neo (Keanu
Reeves) is fired at by another protagonist in the
virtual world was shot not by one motion-picture
camera, but by 120 still cameras mounted in a
roller coaster-style arc and snapping single images
in a computer-driven, rapid-fire sequence. The
resulting effect allows dramatic action, such as
dodging a barrage of bullets, to appear in exagger-
ated slow motion, while the swooping moving cam-
era seems to circumnavigate this stylized slo-mo
subject at normal “real time” speed.Movies Manipulate Space and
Time in Unique Ways
Some of the arts, such as architecture, are con-
cerned mostly with space; others, such as music,FUNDAMENTALS OF FILM FORM 49