The specular and pow factors control the reflection of light from a "shiny" object. The virtual light rays strike an object and reflect (bounce off). For a true reflection, the viewer must be in direct line with the reflected ray to see it. Since the light source is taken to be a single point in space instead of an object with a given size (e.g., a light bulb), a "true reflection" would not look realistic. Therefore the power of the reflected light is set to diminish quickly as the angle between the viewer and the "true" reflected ray increases. This provides the light source with an apparent physical size, similar to that of a spherical light bulb. The color of this specular component (Cs) is given by

Cs = Cl * Fs * cos(a)SHF
where Cl is the color of the light, Fs is the specular factor, cos(a) is the cosine of the angle between the camera and the true reflected ray, and SHF is the specular highlight power factor. Note that the natural color of the object itself does not factor into the specular component.