Color Temperature & Color Rendering

To choose the right fluorescent lamp for a specific application, consider two things:
(1) Color Temperature, and
(2) Color Rendering Index (CRI).

Color Temperature is expressed in degrees Kelvin(K). For example, noon daylight is approximately 5500 degrees Kelvin - the same as our full spectrum Vita-Lite®. Fluorescent lamps with lower color temperatures look red; fluorescent lamps with higher color temperatures look blue. For example, imagine an iron bar being heated. First it gets “red hot.” Then, as it gets higher in temperature, it becomes “white hot” and finally, “blue-white” hot.

Color Rendering Index (CRI) is a numerical system that rates the color rendering ability of fluorescent light in comparison with natural daylight, which has a CRI of 100. This means that a lamp with a CRI of 91 shows colors more naturally than a lamp with a CRI of 62.

Color Selection Guide

Good color rendering is critical in situations where skin tones must appear naturally or products must look appealing. In office and factory applications, high color rendering increases visual clarity, creates a more productive environment, and makes close color matching possible.

The color of an object is determined by the light it reflects. An apple, for example, appears red because it reflects red light. If a light source was deficient in the red portion of the spectrum, there wouldn’t be enough light for the apple to reflect, and it would appear dull or off-color.

Very often, full-spectrum light is appropriate. Other times, it is important to create a certain mood or atmosphere, such as warm lighting in settings where people gather, like restaurants. Other situations will require a specific lamp type such as Color-Matcher 50 for graphic arts applications.

Once you’ve decided on the appropriate lamp finish (daylight, neutral, or warm) or application, it’s simply a matter of determining how much light (lumens) the situation requires.

Duro-Test® offers a wide range of fluorescent color temperatures and color rendering indices. This variety allows you to choose the right lamp for any situation.