Specular Reflection

Angle of incidence: the angle at which light hits a reflecting surface
Angle of reflection: the angle at which light bounces off a reflecting surface
Specular Reflection: the angle of incidence is equal to the angle of reflection
- Seen on smooth, shiny, mirror-like surfaces
If you want to measure these angles, imagine a perfectly straight line at a right angle of 90 deg to the reflective surface (this imaginary line is called ‘normal’).
With a flat mirror, if you measure the angle of incidence and the angle of reflection against the normal, they are exactly the same.
It is easy to show that the angle of reflection is the same as the angle of incidence.

Diffuse Reflection

Diffuse reflection of light: results in light rays reflected at many angles, rather than at just one angle as in the case of specular reflection; angle of incidence is not equal to the angle of reflection
- Seen on rough surfaces
The reflected light from each individual incident ray follows the law of reflection.
However, the roughness of the material means that each individual ray meets a surface that has a different orientation.
The normal line at the point of incidence is different for different rays.
Subsequently, when the individual rays reflect off the rough surface according to the law of reflection, they scatter in different directions.

Water is a reflective surface.
When the water in a lake or sea is very still, the reflection of the landscape is perfect, because the reflecting surface is very flat.
However, if there are ripples or waves in the water, the reflection becomes distorted.
This is because the reflecting surface is no longer flat and may have humps and troughs caused by the wind.

Reflection of light on a concave mirror: when parallel light rays hit a concave mirror they reflect inwards towards a focal point.
Each individual ray is still reflecting at the same angle as it hits that small part of the surface.
Concave mirrors are used in certain types of astronomical telescopes called reflecting telescopes.
The mirrors condense lots of light from faint sources in space onto a much smaller viewing area and allow the viewer to see far away objects and events in space that would be invisible to the naked eye. Also used for make-up mirrors.

Reflection of light on a convex mirror: when parallel light rays hit a convex mirror they reflect outwards and travel directly away from an imaginary focal point .
Each individual ray is still reflecting at the same angle as it hits that small part of the surface.
Parallel rays of light strike the convex mirror and are reflected outwards.
If imaginary lines are traced back, they appear to come from a focal point behind the mirror.
Convex mirrors are useful for shop security and rear-view mirrors on vehicles because they give a wider field of vision.

Angle of incidence: the angle at which light hits a reflecting surface
Angle of reflection: the angle at which light bounces off a reflecting surface
Specular Reflection: the angle of incidence is equal to the angle of reflection
- Seen on smooth, shiny, mirror-like surfaces
If you want to measure these angles, imagine a perfectly straight line at a right angle of 90 deg to the reflective surface (this imaginary line is called ‘normal’).
With a flat mirror, if you measure the angle of incidence and the angle of reflection against the normal, they are exactly the same.
It is easy to show that the angle of reflection is the same as the angle of incidence.

Diffuse reflection of light: results in light rays reflected at many angles, rather than at just one angle as in the case of specular reflection; angle of incidence is not equal to the angle of reflection
- Seen on rough surfaces
The reflected light from each individual incident ray follows the law of reflection.
However, the roughness of the material means that each individual ray meets a surface that has a different orientation.
The normal line at the point of incidence is different for different rays.
Subsequently, when the individual rays reflect off the rough surface according to the law of reflection, they scatter in different directions.

Water is a reflective surface.
When the water in a lake or sea is very still, the reflection of the landscape is perfect, because the reflecting surface is very flat.
However, if there are ripples or waves in the water, the reflection becomes distorted.
This is because the reflecting surface is no longer flat and may have humps and troughs caused by the wind.

Reflection of light on a concave mirror: when parallel light rays hit a concave mirror they reflect inwards towards a focal point.
Each individual ray is still reflecting at the same angle as it hits that small part of the surface.
Concave mirrors are used in certain types of astronomical telescopes called reflecting telescopes.
The mirrors condense lots of light from faint sources in space onto a much smaller viewing area and allow the viewer to see far away objects and events in space that would be invisible to the naked eye. Also used for make-up mirrors.

Reflection of light on a convex mirror: when parallel light rays hit a convex mirror they reflect outwards and travel directly away from an imaginary focal point .
Each individual ray is still reflecting at the same angle as it hits that small part of the surface.
Parallel rays of light strike the convex mirror and are reflected outwards.
If imaginary lines are traced back, they appear to come from a focal point behind the mirror.
Convex mirrors are useful for shop security and rear-view mirrors on vehicles because they give a wider field of vision.