Lumens? Lux? Candela?
The terms "Candela", "Lux" and "Lumen" all have their roots in the Latin language and represent units in the International System of Units (SI).
Lumen (lm) is the unit of luminous flux. Luminous flux measures the total amount of light emitted by a light source in all directions.
Lumen indicates how much light a light source produces in total, regardless of the direction in which it is emitted. It is an important measurement to describe the brightness of light sources such as LEDs. The higher the number of lumens, the brighter the light source.
The candela (cd) is the basic unit for luminous intensity. Luminous intensity measures how much light a light source emits in a specific direction. The unit candela was defined to match the spectral sensitivity of the human eye.
Candela indicates how bright a light source shines in a particular direction. This is particularly important when describing the intensity of light sources such as lamps or spotlights, especially when focused or directed.
Lux (lx) is the unit of illuminance. Illuminance measures how much light falls on a specific area. More precisely, one lux corresponds to one lumen per square meter (1 lx = 1 lm/m²).
The lux specification indicates how strongly the light is distributed on a surface. This is particularly relevant when describing the brightness in a specific area or room. For example, illuminance is used to ensure that there is sufficient light in various environments, such as offices, living spaces or public areas, to meet needs and requirements.