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Color and Lighting

I recently replaced the lighting in my studio, and in the process gained quite a bit better understanding of how different lights affect our perceptions of color.

There are two questions that you need to consider in this realm.

  • What color is the light?
  • How well does that light allow you to differentiate colors?
  • The color of the light can be expressed two ways: in words (Warm White, Cool White, Daylight) or in terms of color temperature (expressed in degrees Kelvin. e.g. 6500K). This can make a big difference. I have cool white lamps in one room (4100K) and the new lights have a cooler rating (5000K). They are noticeably bluer (or whiter, depending on which light you have gotten used to. ‘Daylight’ florescent lamps are cooler still at 6500K. Real daylight actually varies quite a bit: direct sun, northern light, overcast days, early morning, late afternoon all have different colors. I chose the 5000K lamps as a nice compromise. To me they seem to approximate the light you would see coming through a north facing window.

    Why is the color of the light so important? Remember that our inks work by absorbing and scattering the colors that are present in the light that strikes them. Those colors can move quite a bit with the color of the light we are viewing them under.

    The second factor, our ability to differentiate different colors, depends on what frequencies of light are in the white light mix. This is sometimes expressed for a given lighting option as a ‘Color Rendering Index’ or CRI. My old lights were High Intensity Discharge (HID) metal halide lamps. They were ok from a color temperature perspective (although the lamps were getting old, so they were not very consistent) but they score only fair on the CRI scale at 65. The new florescent lamps do better with a CRI of 85 (considered excellent) although cheap tubes may not do this well. Incandescent lamps score still better with a CRI of 100, but this is by definition: the CRI is less meaningful for color temperatures below 5000K (most incandescent lighting is considerably warmer than that: in the 3500K range)

    If all of this seems a little mind boggling, it is for good reason. Color science is complicated stuff. Does the average artist need to know all of this? Perhaps not, but as it is with pigments, the better we understand the factors that affect our color perception, the better job we can do of exerting conscious control over the color in our work. Control is about choices, and conscious choice in the production of art is always a good thing.

    About the Author:

    Dean Russell Thompson is an Artist and Printmaker working in Loveland, CO.