Lux (lx) is the unit of illuminance.

 

Lux is the amount of light falling on a unit area (m²). In other words, Lux is the number of lumens per square metre (lx=lm/m²). The amount of lux is therefore affected by the distance between the light source and the surface.

 

If you hold a surface 1 metre away from a light source, it is logical that it will receive more light than if you hold it 5 metres away from this light source. Lux is used to determine this amount of light.

 

To know whether a room has enough lighting, this unit is therefore most commonly used. After all, light itself is not visible, it only becomes visible when projected onto something. When you want to know how much light a torch gives, you will therefore focus the light on the wall or another surface.