NALMCO Certified Apprentice Lighting Technician (CALT) Practice Exam

A lamp's color rendering ability describes its capacity to do which of the following?

1. Prevent color shifting over time

2. Raise color temperature over time

3. Show colors accurately

4. Produce light per unit of consumed energy

The correct answer is: Show colors accurately

The correct answer highlights a lamp's color rendering ability, which fundamentally refers to its capacity to show colors accurately in comparison to natural light. This characteristic is measured by the Color Rendering Index (CRI), which ranges from 0 to 100. A higher CRI indicates that a light source can render colors more similarly to sunlight, allowing objects illuminated by the lamp to appear more vibrant and true to their actual colors. This is crucial in environments where accurate color perception is important, such as in art studios, retail spaces, and medical facilities. The other choices do not define color rendering accurately. Preventing color shifting over time relates more to the longevity and stability of a lamp's spectral output rather than its ability to render colors accurately. Raising color temperature over time pertains to the lamp's operational changes as it ages, which also doesn't directly reflect color rendering capabilities. Producing light per unit of consumed energy refers to the lamp's efficiency (often measured in lumens per watt) but does not relate to its ability to depict colors accurately. Thus, the focus on accurate color representation makes the selection of "show colors accurately" the correct choice.