conditions.
These characteristics will vary with changes in spectral
quality and intensity of illumination.
Since it is impossible to specify
color under all conditions of illumination, most colors are identified when
viewed under normal daylight or tungsten light conditions.
Three terms used to help identify color are hue, brightness, and saturation.
Use them as tools to assist in color communications. If we are to be more
explicit in color communication, we should know something about these terms.
a. Hue. Hue is a term
used to assign a general color to the subject.
If we say the subject is
red or yellow, we are identifying the hue.
However, there are as many
shades as wavelengths in that portion of the
spectrum.
If we assign a
hue only, we are less than specific in color
identification.
b. Brightness.
Another descriptor of color is brightness, such as
light green or dark red.
Light and dark are relative descriptors and are
subjective. This is an attempt to describe the brightness of the color and
is some measure of its absorption and reflection characteristics.
c. Saturation.
Saturation describes the purity of a color.
If the
color is pure, it could be called a brilliant color, as a brilliant red.
Impure colors appear dull. Determine saturation by comparing the color to a
neutral gray of the same brightness.
The problem with color identification is that one term used to identify a
color might have a different meaning for other persons. For example, each
individual has their idea of what light green looks like. In an attempt to
standardize color identification, the Munsell and CIE systems of color
specification were developed. While helpful, their usefulness is limited by
the physical and psychological difference of the individuals using these
systems.
7.
Color Temperature.
The color spectral quality of the light used to illuminate the subject plays
an extremely important part in color photography.
Color temperature is a
useful means of identifying the spectral quality of certain types of light
sources. Since the use of color temperature to describe a light source can
be misleading, let's examine this subject more thoroughly.
a. Kelvin Color Temperature System.
Experiments by Lord
Kelvin developed the color temperature system that bears his
name.
The Kelvin ratings of the most commonly used light
1-16
SS0514
Previous Page
