Light can be measured and described using various units depending on the specific aspect being measured. Here are some commonly used units for different properties of light:
Intensity/Illuminance: The amount of light energy per unit area. The SI unit for illuminance is the lux (lx), which is equal to one lumen per square meter (lm/m²).
Luminous Flux: The total amount of visible light emitted by a light source. The SI unit for luminous flux is the lumen (lm).
Radiant Flux: The total amount of energy emitted by a light source, including both visible and non-visible electromagnetic radiation. The SI unit for radiant flux is the watt (W).
Luminous Intensity: The power emitted by a light source in a particular direction. The SI unit for luminous intensity is the candela (cd).
Wavelength: The distance between successive peaks or troughs of a light wave. It is typically measured in meters (m), but for convenience, smaller units like nanometers (nm) or angstroms (Å) are often used.
Frequency: The number of wave cycles passing a given point per unit time. It is typically measured in hertz (Hz), where 1 Hz represents one cycle per second.
These are just a few examples of the units used to measure different aspects of light. The specific unit used depends on the property being measured and the context in which it is being studied or applied.