What does reflectance measure?

Reflectance measures the percentage of light that a surface reflects back into the environment rather than absorbing it. This property is crucial in various fields, including optics and photography, as it directly influences how surfaces appear under different lighting conditions. Understanding reflectance is essential for applications that involve light interaction with surfaces, such as designing camera sensors, evaluating image quality, and setting up effective surveillance systems with video cameras.

While the speed of light on various surfaces is a related concept, it does not define reflectance. Similarly, the amount of heat a surface absorbs pertains more to thermal properties than to reflectance. The intensity of colors detected relates to how colors are perceived based on various factors, including light conditions, but does not specifically quantify how much light a surface reflects. Thus, the measurement of reflectance is fundamentally tied to the percentage of light returned by a surface.