Susan Troller asks Randall Whitehead about the emotional ramifications of light for The Artful Home, 7.13.05

ST: Randall, how does lighting impact our moods?

RW: It has a profound impact: this applies to both to natural and electric lighting. I think that on a physiological level we are all solar powered. If we experience 3 days or more of clouds or rain, all the energy seems to drain out of us. The moment the sun appears our whole mood changes and our energy level soars.

Electric light can also play an important role on how we feel in a space. I talk a lot about the functions of light: decorative, task, accent, and ambient. Each of these functions of illumination plays an important role, but any one light source by itself can create a less than desirable effect. For example, accent lighting helps add depth and dimension to a room. If it is the only source of illumination it creates what I call the museum effect, where the art appears to be more important than the people in the space.

Ambient light is an indirect source of illumination used for reducing shadows on people's faces, but if it is the only light it creates a cloudy day effect where everything in the space has the same flat value. It is the thoughtful layering of various lighting sources together that results in a space that both welcoming and subtly dramatic. I want homeowners and their guest to feel immediately comfortable upon entering the house.

ST:How does good lighting enhance art?

RW: Many people are not aware that natural light and incandescent light are very different in color. People will consciously or unconsciously seek out natural light to see the true color of an item, whether it is an article of clothing, a rug sample, tile selection or paint chip. They are absolutely right in doing this. Daylight has perfect color rendering capabilities. Why? Because daylight is really a blue-white source of illumination. It is this color quality that renders colors most true. Yet, this same quality of light may not be the perfect choice for skin tones.

At night most people are more comfortable under the yellow hue of incandescent light, because it is what we grew up with. Sadly, under incandescent light colors can shift dramatically. Red will shift to orange, blue will shift to green and white will shift to amber. While this may be okay for people, this can really distort the color of artwork.

The challenge as a lighting designer is to create an environment that is both comfortable for people and positive colorwise for art. In order to accomplish this not only do I layer decorative, accent, task and ambient lighting together. I also layer the color of the light as well. The glow of indirect illumination for a space will come from a warm light source, while the accent lighting for the art will be much cooler in color. This can be done with special lenses that filter out the yellow tone of incandescent light. This whiter light will allow art to visually pop, while allowing people within the same space to bask in the warm radiance of a more incandescent quality of light.