Specular Reflection - Definition

There are two types of reflection: specular and diffuse. Specular reflection is a type of surface reflectance often described as a mirror-like reflection of light from the surface. In specular reflection, the incident light is reflected into a single outgoing direction. The name specular is derived from the Latin word speculum, meaning mirror.

Specular reflection obeys the Laws of Reflection and the light is reflected from a smooth surface at a definite angle. Specular reflection occurs for all polished and smooth surfaces, like mirrors. The angle of reflection in specular reflection is equal to the angle of incidence. Rough or unpolished surfaces are not good specular reflectors as they do not reflect light at the same angle as the angle of incidence.

Mirrors that are used for specular reflection are usually made of metals such as aluminum or silver. Specular reflection is measured using incidence reflectometers by scanning a variable wavelength source.

References

• Specular and Diffuse Reflections – Florida State University
• Reflection and Refraction – University of Wisconsin
• Basic Principles of Surface Reflectance – Carnegie Mellon University