Why do objects look different under different lighting?
Picture a green leaf on a sunny day. Why does the leaf look green? When sunlight strikes the leaf, molecules inside the leaf absorb some of the energy of the light. Some wavelengths are absorbed more than others. This is the source of energy that a plant needs in order to grow. The wavelengths of sunlight that are not absorbed by the leaf are reflected. When you look at a leaf, you see the light that is reflected from its
surface and you perceive this light as green. What happens if the light that strikes the leaf is not sunlight, but rather light from a red stage light that produces only light in red wavelengths? In this case, the leaf absorbs all of the light that strikes it. When no light is reflected or emitted, an object appears to be black.
There are several kinds of artificial light used in buildings. Although the light they produce generally appears to be white, none of these light sources produce a spectrum of light that exactly matches sunlight in distribution and relative intensity of wavelengths. They also differ from one another. For example, incandescent light (light bulbs) tends to produce more light in red and yellow wavelengths compared to sunlight. Standard fluorescent tubes tend to produce light that has a greater proportion of violet and blue wavelengths. The light that is reflected from an object varies depending on the wavelengths of light that strike it. That is why a paint chip may appear different under different types of lighting. Some stores that sell paint offer a place where the colors can be observed under varying types of light.
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Filed Under: Science
