For a spherical surface is illuminated a region has bright spot which is white in color in a specific region. This reflection in the specified region is known as specular reflection.
Here, L = Unit vector directed towards light source
R= Unite vector in direction of ideal specular reflection
N= Unit normal vector
V= Unit vector pointing to viewer.
b= Viewing angle
For a perfect mirror, V and R coincides, i.e. a=b