Luminous intensity refers to the visible light emitted in a specific direction, measured in candelas (cd).

A light source with a luminous intensity of 1 cd can emit a luminous flux of 12.57 lm.

Luminous flux refers to the total amount of visible light emitted by a light source, representing the light source's ability to emit light. The unit is lumen (lm).

So how should we apply this when shopping in our daily lives?

We can check the product specifications for power (W) and luminous flux (lm). A higher luminous efficiency value indicates a brighter light.

Therefore, under the same environment, if we want to achieve the same brightness, a light source with lower luminous efficiency will consume more electricity.

Illuminance refers to the luminous flux incident on a surface area, commonly used to indicate the brightness level of a space or illuminated surface. The unit is lux (Lux).

Illuminance standards are not just technical terms; the CNS illuminance standards are important indicators in lighting design and are closely related to our daily lives. Appropriate illuminance can enhance our quality of life and protect our eyesight.

Luminance refers to the intensity of light emitted or reflected by an object when viewed from a certain direction, such as screens and illuminated signs. It clarifies the relationship between these lighting terms and the eyes through illustrations.