Measurements of light

Measurements of light quantify its properties, including brightness, color, and intensity. Key measures include luminance, which indicates how bright a surface appears; illuminance, showing how much light falls onto a surface; and luminous flux, representing the total light emitted by a source. Color is assessed using parameters like correlated color temperature (CCT) and color rendering index (CRI), which describe the warmth and accuracy of colors under a light source. These measurements help engineers, designers, and scientists evaluate lighting for comfort, visibility, and energy efficiency across various applications.