angle of incidence: Quick Facts

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Two diagrams compare light reflection: the top shows blue incident and reflected rays bouncing off a smooth surface, with equal angles from the normal; the bottom shows rays scattering from a rough surface, with normals and angles marked at various points.

$Snell's law diagram showing an incident ray striking the boundary between media n1 and n2, reflecting at equal angle theta 1 and refracting toward the normal at angle theta 2.$

Law of reflection diagram showing an incident ray and reflected ray meeting a flat surface at equal angles on either side of a dashed line normal to the surface, theta 1 equals theta 2.

$Figure 7: The refraction and reflection of light. (Left) When light strikes the boundary between glass and air at less than the critical angle (θc), it is refracted and partially reflected; (centre) when it meets the boundary at the critical angle, it is refracted parallel to the boundary; (right) when it meets the boundary at more than the critical angle, it is reflected totally.$

Diagram showing light from a bee reflecting off a vertical plane mirror into an observer's eye; equal angles of incidence and reflection produce a virtual bee image behind the mirror.

What happens during total internal reflection of light?

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angle of reflection grazing incidence critical angle angle of refraction refraction reflection

angle of incidence: Quick Facts

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