For all mirrors, the distance of the object from the mirror is designated by o, while the distance of the image from the mirror is designated by i. All spherical mirrors have an associated center of curvature C and radius of curvature r. The two types of spherical mirrors are concave mirrors and convex mirrors. If a complete sphere were mirrored on both sides, a person standing on the outside would see a convex mirror, while a person standing on the inside would see a concave mirror. Concave mirrors have a focal point F located at the midpoint of the line joining the center of curvature and the mirror. The focal point is at a distance f from the mirror, where f is known as the focal distance. The focal distance is equal to one-half the radius (r). Concave mirrors are known as converging mirrors, while convex mirrors are known as diverging mirrors.
