Moving Images, Understanding Media

Chapter 4 Storytelling with Light 123

The Essence of a Medium

Look around you right now. What is the source of the light

that allows you to read the words on this page? Are you

indoors? Outdoors or near an exterior light source? What

kinds of light are illuminating what you can see right now?

Can you see shadows?

Th e human eye is a very eff ective receptor and interpreter

of light. Th e eyes and brain adjust instinctively to make

what we see more palatable to our senses and more pleasant

to watch. People tend to take this for granted. However,

photographers must train themselves to be able to understand

what the camera, fi lm, or other preserving materials are

able to capture and reproduce.

As you have learned, photography was invented as a result

of experiments involving chemical reactions and the eff ects

of light on diff erent surfaces. A key issue to consider is the

component of traditional photography known as grain. Th e

surface impression of traditionally photographed pictures,

whether for still or moving images, includes particles that

register as tiny grains as they are exposed and developed.

As the silver-halide crystal particles react to light and

emerge they help to give a photograph or motion picture

a particular texture, quality, and luminescence. Th e grains

diff er in distribution, size, and density according to fi lm

type, the light that hits the fi lm, and how it is processed.

Typically, the grains are well distributed when there is

proper exposure to a particular type of fi lm. On the other

hand, the grains generally cluster together when there is too

little or too much light or when fi lms are reprinted through

many generations.

Digital Capture of Light

With digital cinematography, the recording medium does not involve chemical

particles embedded in a surface, so there are no physical grains reacting to

the light. Instead, the light is electronically converted into the binary code

known as bits. Computers function using strings of 0s and 1s , and digital

photography works in the same way.

As light passes through the lens and into the body of the camera, it strikes

a photographic sensor that contains a light-sensitive grid that registers light

in pixels. Each pixel contains a single measurement of the light’s brightness

and color at that exact spot, with the number of bits per pixel determining

the detail of that information. As a result, the quality of a digital image

depends on the number of pixels making up the frame and the number of

bits per pixel. Th e quantity of pixels is measured in width by height (such as

Figure 4-2 Charles and Ray Eames, who

headed one of the most creative and

infl uential design and arts studios of the

twentieth century, shooting one of their

playful and enlightening short fi lms, Toccata

for Toy Trains. (Courtesy Time & Life Pictures/

Getty Images)

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