Gray versus color - an essay
Black and white photos? This day and age? They are old fashioned! Passé! This is the age of hi-tech! Who has the patience to bother with obsolete stuff when we have digital cameras taking 24 megabit photo files with 24 bit color?? Well, let’s think about that.
======================== For the purpose of analyzing vision we can say that light is energy in the form of a wave. Light waves are reflected by the surface of objects, and when this reflected light enters our eyes and reaches the retina, receptor nerve endings are stimulated to send signals to the visual cortex. The cortex processes the signals and the result is what we consider to be an image of the object we see. Details of the image are influenced by a variety of factors. Let’s take color. Light waves come in an infinite variety of wave lengths, which correspond to shades of color. The material of the surface of objects will absorb certain wave lengths better than others, and thus the color of the light reflected off the surface may be quite different from the color of the light source. Receptors in our retina respond to specific wave lengths, and the resulting color sensation we get needs to be further interpreted by the brain. We know that a newborn baby can see when she reacts to a view of something or other. Perhaps it is a red rose. But the baby cannot yet have a clearly formed concept of what “red” is. She may be able to distinguish it from a yellow rose, but she cannot know why. As the baby learns to speak, she will learn that the rose is red, meaning, red is what we call that shade in English. But if the baby is French, it may turn out that the same rose will be labeled “orange” in that language. So |
linguistic culture will influence what color we see.
There are also internal, physiological factors that influence vision. The density of color receptors on the retina influences our ability to distinguish slightly different shades and the contrast between them. This density varies from person to person and affects the color details perceived by different individuals. There can also be defects in the color receptor nerve endings. An extreme case of this is color blindness. We take our vision entirely for granted and most of us are blissfully unaware of the complexities of all the factors involved in the process the brain has to go through to provide us with a color image. And we are also unaware of the fact that individual images our brains forms of the same object may, in fact, be quite different from one person to another. Is color even necessary to form an image? Absolutely not. It is clear that most animal species have no color vision. Color receptors are a relatively new evolutionary trait. Yet the species without them rely on their vision to avoid predators every bit as effectively as higher order primates do. And early photographs, as well as graphic images (such as line drawings, pencil drawings, wood cuts, etchings, etc.) produce images that are considered realistic and sufficient in every way. So what property of light do we need to help us form a satisfactory image? We certainly need a certain minimal level of light energy, or intensity of light. Our eyes can adjust to darkness, but only within limits. If there is insufficient light, we may see nothing, or can only develop a vague sense, an uncertain approximation of objects that may be there. |
When there is adequate light we depend on contrast levels of reflected light to form an image of a solid, three dimensional object. The more light reaches our retina the lighter the image that is formed. The various surfaces of an object reflect a different fraction of the available light, depending on the angle from the light source and the angle of the surface to us, the observer. Thus the various surfaces of an object vary in degree of lightness and darkness as perceived by our eyes. It is this variation in light intensity, or contrast, that enables us to form a three dimensional image of the object.
Early photographic technology was based on reproducing this difference in contrast levels, in the form of various shades of gray, from white to black. The resulting gray images were considered perfectly adequate and realistic. This proves that color is not a required component of a realistic and complete image representation of an object, but in a way, is only an added luxury, or refinement. Color provides added detail, but not a necessary, or minimal content. |
And some of the most famous, highest impact photographs in the history of the art form are black and white. Ansel Adams and Robert Capa come to mind, among many others. The emotional impact of a dramatic image, whether that of a monolithic rock in moon light or of the devastation of war, are captured by artfully using shades of light, contrasts, reflections, highlights – in other words, just light levels without color. Color can sometimes distract from the raw emotional mood of a fine black and white composition.
Of course, there is nothing wrong with color photographs either. There are images where color can be very important. A close-up of a peacock displaying his tail is likely to be more spectacular in color than in black and white. Or the famous photo of the girl with incredible green eyes on the cover of National Geographic would be much less impressive in black and white. So the bottom line: neither is better than other. They are different media. Different art techniques, like etching and silk screen. |