Convert lux [lx] to candela steradian/sq. meter Online | Free lllumination Converter

The Standard Unit of Illuminance

Lux (lx) is the SI unit of illuminance, measuring the amount of luminous flux (light) falling on a surface per unit area. One lux is equal to one lumen per square meter (lm/m²). It quantifies how brightly a surface is illuminated, directly relating to human visual perception of light in an environment.

Lux is widely used in various fields such as architecture, photography, horticulture, and workplace safety to ensure proper lighting conditions. For example, typical office lighting ranges from 300 to 500 lux to promote productivity without causing eye strain. Outdoor daylight varies greatly but can reach up to 100,000 lux on a bright sunny day.

Because lux is based on the metric system, it is the preferred unit globally for lighting measurement and design. It helps engineers, designers, and scientists create environments with appropriate lighting levels, balancing visibility, energy efficiency, and comfort.

Understanding lux is essential for interpreting lighting standards, optimizing artificial illumination, and assessing natural light exposure, making it fundamental in both everyday life and technical applications.

Understanding Radiance

Candela steradian per square meter (cd·sr/m²) is a unit of radiance, which measures the amount of light power emitted, reflected, or transmitted from a surface in a specific direction per unit area. It combines the candela (cd), which quantifies luminous intensity, with the steradian (sr), the unit of solid angle, and divides by the surface area in square meters.

Radiance describes how bright a surface appears when viewed from a particular direction and is critical in fields such as optics, imaging, computer graphics, and remote sensing. Unlike illuminance (which measures light falling on a surface), radiance tells us about the directional brightness coming off or through a surface.

This unit helps in characterizing light sources and reflective surfaces, allowing scientists and engineers to model how light behaves in complex environments. It is essential for designing lighting systems, calibrating cameras, and simulating realistic visual scenes.

Understanding candela steradian per square meter allows precise control over brightness and directional light properties, supporting advancements in display technology, vision science, and photometric measurements.