How we see the color of a subject depends upon the inherent
nature of that subject and how it absorbs and transmits the various wavelengths
of light that we perceive as red, blue, etc. In essence, things absorb some
frequencies of light more than others, then reflect or transmit light as its
color. If something looks white (such as brightly lit snow), the wavelengths of
all the colors have interfered with one another and canceled, in
effect, any color out. If a thing is black, it absorbs all the frequencies and
reflects none of them back.
But the subtlety, the shades and variations of color, are
determined by other factors a well. While the subject itself has a “base” color
(its selective absorption and transmission of light), the brightness level and
direction of the illumination that reveals it, the surface of the subject, be it
rough or smooth, and the color cast created by light source itself also have a
strong influence on the color we see and record. There is always a dance among
the quartet.
If you look at a tree with a very dark bark backlit by a
bright light source, it will look almost black. Look at the same tree with a
shaft of light striking it (or illuminate it with flash) and that black may
appear brown or even yellow. We more or less take this for granted, and say
that the tree is lighter because it's being struck by direct light. Part of
that change, however, may result from the effect of the tree's surface, and how
it alters the absorption and reflection of the light. Thus, the textural
surface can affect how we see the subject brightness and its color.
Late day in northern New Mexico often yields a rich, warm light, the result of the sun's rays slanting low across the western horizon. This ambient light has a strong effect on all the colors within the scene, tinting them in reds and yellows.
The overall quality of the light source can have a profound effect on color. Light and dark tints of color that in flat light would show as one hue become more differentiated in bright light--the effect of color contrast. Yet, if that light is too bright and the surface is glossy we will get greater interference, thus some of the color that we might see in flat light becomes "washed out", overly bright or at least considerable lighter in tone. If the surface is matte, the reflection becomes more diffuse, and we see more color. Thus, the greater the surface reflection, the less the color richness, or saturation we perceive. Rough surfaces throw off all sorts of reflections that can vary the color in many ways, and create a more dimensional effect.
Direct light has a strong influence on how we see color, enhancing contrast and differentiation, especially on rough or highly textural surfaces, such as on the bark of this desert cottonwood in late winter.
A strong influence on color perception is the color bias, or
nature of the overall light source itself. Atmospheric effects are a case in
point, with perhaps the most familiar being so-called “aerial perspective.” If
you look at a range of mountains from a distance on a summer’s day, we see them
as blue. When we walk or drive closer to them, however, we see them as green,
or red, or whatever color they might be. If the ambient (overall) light source has a color cast it may well dominate the way we see color of every subject in the scene.
The same goes for the visible color changes subjects undergo
throughout the day. The inherent color, if you will, of sandstone formations do
not change, but we all know that photographing those formations late in the day
when the slanted rays of sun strike them will yield be the most saturated and
vivid effects. The colors may become even more enhanced due to the fact that
those rays of light are more amber, which is the color bias of sunlight as it
skims across the horizon.
Color proximity has a strong influence on how we see various forms within a scene. This is especially true in autumn when some greens remain among the reds and yellow of neighboring foliage. This color contrast evokes a kind of visual "vibration" to our eyes.
One other factor to consider is the influence of color
proximity. The color of any one thing does not exist in a vacuum. It is
influenced by the color of subjects around it, and how those subjects absorb
and reflect a certain wavelength of light. It's as if we exist in a world of
color mirrors, reflectors that bounce from one subject to another. This sets up
color relationships, and creates many of vibrations between colors that
diminish or strengthen color contrast.
In short, the way we see color is almost subjective--it is
certainly conditional. Our perception of color itself is always changing, always being affected by the energy around it.
Next post: Color Relationships
