What is measured in candelas and relates to light perception?

The measurement in candelas relates to light intensity, which quantifies how much light is emitted in a particular direction from a source. This metric is pivotal in the field of photometry, which studies visible light as perceived by the human eye.

Intensity, measured in candelas, directly correlates with our perception of brightness. While brightness is a subjective experience influenced by other factors, intensity is an objective measurement referring to how concentrated the light is. Thus, when assessing how light affects our perception, intensity serves as a fundamental parameter, providing a clear, standardized way to communicate the strength of light from sources. This makes the concept essential for applications ranging from photography to interior design, where understanding how light interacts within environments is crucial.