Imagine that you are a buyer for a clothing retailer. You've investigated the fashion trends at industry shows to select a line of clothing for the coming season. But the time and money invested upstream in producing the exact color originally selected may come to naught unless the product is displayed under well-controlled lighting. Uncontrolled light can lead to poor color quality and, ultimately, a loss in sales. Defects in the light sources or in their arrangement, and natural light from a nearby window, can corrupt store lighting. Many shoppers are familiar with the problem of purchasing a garment in a store, only to find that the color looks very different at home. The effect that occurs when two products appear to be the same color under one set of lighting conditions but are different when the lighting is changed, is called metamerism. Research using the LightSpex spectroradiometer could help managers optimize the lighting in their stores. The American Association of Textile Chemists and Colorists and student researchers from the College of Textiles at North Carolina State University are using the LightSpex spectroradiometer from McMahan Research Laboratories to quantify lighting variability in retail stores. Their goal is to enhance color control and enable store managers to optimize the lighting under which they display their merchandise. In addition, spectroradiometric measurements make it possible to match colors to a specific lighting condition in a particular area of the store; e.g., in the dressing rooms or in the shop window. The LightSpex made the study possible, as no other device comparable in price was identified, said David Hinks, a professor at the university who is leading the students' research project with the assistance of Robert K. McMahan, president of McMahan Research. To verify the lighting, the students measure the spectral distribution of the light sources and quantify its variability throughout the store. The change in light is then quantified by spectral distribution, color temperature and color rendering accuracy. The LightSpex compares the light it measures with standardized illumination data established by the International Commission on Illumination (CIE). These standards are used to indicate how the color of a particular product will be perceived under given standard conditions. With the spectroradiometer, the perceived color can be computed under any spectral incident light and compared with CIE's standardized lighting. D65 (daylight at 6500 K) is the recommended lighting standard for visual color evaluation of textiles. Hinks said the handheld device is user-friendly and ideal for fieldwork. "I was also pleasantly surprised by the price," he said. The device fills a need that could not be met by cameras in the same price range. Hinks also noted that the LightSpex could have significant industrial applications, such as in upstream textile production facilities.