Modern color measurement technologies go beyond the subjective human gaze and allow us to objectively quantify a rainbow of colors. Image Source: Unsplash user Denise Chan
Color surrounds us every moment of our lives and affects our emotions, behaviors, and beliefs in large and small, conscious and unconscious ways. Color can set a mood, warn us of danger, give us critical information, and even bring us joy. Despite the universal presence of color, describing it remains elusive, in part due to variations in color perception from person to person and in part due to a lack of descriptors for each of the millions of shades seen by the human eye.
Instrumental color measurement moves beyond the limits of human perception and vocabulary and allows us to capture color information as objective data, creating a common language of color that is essential for communication within and between industries around the world. The two most advanced color measurement instrument types are colorimeters and spectrophotometers, both of which use sophisticated technologies to accurately and precisely quantify and define color.
While closely related, these instruments have unique qualities that may make one more suitable than the other for a particular type of measurement.1 Understanding the characteristics of a colorimeter vs. spectrophotometer can help you select the best tool for your application.
Colorimeters are ideally suited for evaluating final color results and identifying unwanted color variations. Image Source: Pexels user Karolina Grabowska
What Is a Colorimeter?
A colorimeter is designed to perform a type of psychophysical sample analysis by mimicking human eye-brain perception, which means its measurements correlate to human perception.. In other words, it is designed to see color the way we do.
Its results are direct and read as tristimulus values. A tristimulus value is one that identifies a color with characters that represent different dimensions of its visual appearance. A tristimulus value may contain values like X, Y and Z or L, a and b. The “gold standard” for tristimulus colors is the CIE Color System, developed by the International Commission on Illumination — the CIE in the title stands for the French version of their name.
There are a few unique components involved in a colorimeter.
- Illuminant: The illuminant represents a specific light source, such as daylight or incandescent light, to project consistent brightness onto the object. In a colorimeter, an illuminant is fixed.
- Observer: The standard observer offers a specific field of view with which to analyze the colors. A colorimeter usually uses a 2-Degree Standard Observer, which is suitable for color evaluation and quality control.
- Tristimulus absorption filter: The absorption filter isolates specific wavelengths to be applied to the sample.