Other Considerations
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COLOR Other Considerations |
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LIGHT PROPERTIES
All color mixing needs light. Without light, we would see nothing at all. When we are dealing with paint colors, we are seeing these colors as a result of reflected light.
A white light approximating sunlight is needed to see a full range of color. If we were to look at a pallet of paint colors with only a red light source, we would see only shades of red. We would not be able to see green or blue hues under a pure red light source. Yellow would appear red.
For a painter, the source of light is important. It can actually make a difference in the appearance of the final painting. So you may hear a painter using sun and skylight from a certain direction, such as northern light. Artificial light sources vary in their color mixtures. We hear of cool or warm fluorescent lighting. If we mix color paint under these different light sources, the resultant colors may vary somewhat. The variation would appear even greater were it not for color vision adaptation.
COLOR VISION ADAPTATION
Our eyes automatically adjust to the quality of a light source in order to match a standard of viewing that is part of the human eye-brain system of perception. We look at a pink rose in morning sunlight and it appears pink. We view the same rose at sunset and it looks the same pink color. We look at the same rose under cloudy skies and it still appears "pink". But if we were to photograph this rose under these three conditions, the pink of the rose would vary greatly. Its pink petals may be tinged with blue, orange, green, gray or some other hue. This is caused by the quality of the light.
Modern digital film cameras have automatic "white light balance" features to overcome variations due to the source of the light. The human vision system also functions to make colors appear consistent across a wide range of lighting conditions. However, there is a limit to this adaptation. Under a red light, most colors will appear various shades of red. Green and blue light would need to be added for our eyes to discern the actual colors as usually seen under "white" light.
UN-MIXING COLOR
For the most part, we cannot readily see the original colors from viewing the resultant mixture. Green does not usually appear as a cyan-yellow hue. It usually appears as just "green". But with experience artists may develop the ability to ascertain what colors would result from certain mixtures.
The same is true with light. We see white light as being white, not a mixture of colors. We usually see yellow light as being only yellow and not a mixture of red and green color.
This diagram shows how light from a yellow lamp can be broken up into its component colors.
A glass or plastic prism can be used to demonstrate that light is a mixture of color. The prism bends green illumination at a different angle than red illumination. This causes the colors to shine on different areas of a screen or wall. The yellow light is broken up into its component colors and shows that it is actually a mixture of green and red light.
| It should be noted that not every light source has the same mixture of hues even when they appear the same color. For example, some light sources use gases to create different hues. These light sources can produce a very narrow band of spectral color. With such a light source, a yellow colored light may be close to a pure spectral yellow. In that case, a prism will show only yellow. |
| All images are original graphics or photography
by Robert Truscio © 1997- 2009 (All rights reserved) |