Reflection
Plane mirror
Consider a source point A sending light rays onto a plane mirror. A simple construction of the
reflected rays shows that all the emerging rays seem to come from a point A', virtual image of
A. In the same way, if we reverse the direction of the light, we see that the image of a virtual
object placed in A' is a real image placed in A. The plane mirror is therefore strictly stigmatic.

Conjugation relationship
The position of the image relative to the mirror equals the position of the object relative to the
mirror. The image A' is symmetrical to the object A in relation to the mirror

Where H is the orthogonal projection of A on the mirror: the image of A is the orthogonal
symmetric of A
The object and the image are of different natures :
- Real Object-Virtual Image
- Virtual Object-Real Image
The size of the image equals the size of the object :

Spherical Mirror
A spherical mirror is a reflective spherical surface with a center C, a vertex S, and a radius of curvature R. There are two types of spherical mirrors : Concave (𝑹 = (SC)< 0) and Convex (𝑹 = (SC) > 0)

The conjugate relationship for a spherical Mirror :

The magnification 𝜸of a spherical mirror :

The focal distances SFet SF' have the following expressions :
