Luminous flux, also known as luminous power, is the measure of the total amount of visible light emitted by a light source. It is the quantity that describes the brightness of the light source in terms of the human eye's sensitivity to different wavelengths of light.

Common units of measurement related to luminous flux include lumens (lm), which is widely used to measure the total amount of light output from a light source. Another related unit is lux (lx), which measures the amount of light that falls on a surface. These units are essential in determining the brightness and effectiveness of lighting solutions in various applications.

• Luminous flux is crucial in designing lighting systems for buildings, streets, and vehicles.
• It helps in evaluating the energy efficiency of light sources.
• Luminous flux plays a significant role in the field of photography and cinematography for achieving desired lighting effects.