Absorptance
Light absorptance is the ratio of absorbed to incident light on a material.
Behaviour of Light
The behaviour of light can sometimes be quite complex in its simplicity.
Colour
Information on how we perceive the colour of materials and objects.
Light Reflectance
Reflectance measures the ratio of reflected light to total incident light.
Light Refraction
Refraction is the bending of light when it moves between materials.
Light Refractive Index
The ratio of the speed of light in a vacuum to the apparent speed of light in a material.
Light Transmittance
Light transmittance is the ratio of transmitted to incident light through a material.
Lux
Reflectivity and Reflectance
Reflectance and reflectivity values are often the same, but the concepts certainly aren't.
Specularity
Specularity is a surface property affecting the angular distribution of reflected light.