Diffuse reflection of light from an irregular surface of an object
When a parallel beam of light is incident on a rough surface, it is reflected in many directions. This is called Diffuse or Irregular Reflection.
Although each ray obeys the law of reflection, different surface angles that light rays encounter in striking a rough surface cause reflection in many directions. The different portions of the surface reflect the incident light in different directions. We can see the objects around us because they reflect light in a diffused manner and we are able to see without a glare.
The distances between successive elevations on the surface are less than about one–eighth the wavelength of the light, then there is very little diffuse reflection, and the surface is said to be polished. Same surface therefore may be polished for radiation of long wavelength but not polished for light of short wavelength.
In diffused reflection, the light spreads in all directions giving the same brightness, whereas in the case of a plane mirror, the brightness is not the same when viewed from any direction.