Spherical mirrors may be concave (converging) or convex (diverging). The focal length of a spherical mirror is one-half of its radius of curvature: f=R2. The mirror equation and ray tra...Spherical mirrors may be concave (converging) or convex (diverging). The focal length of a spherical mirror is one-half of its radius of curvature: f=R2. The mirror equation and ray tracing allow you to give a complete description of an image formed by a spherical mirror. Spherical aberration occurs for spherical mirrors but not parabolic mirrors; comatic aberration occurs for both types of mirrors.
