Radius of Curvature (R)

Definition

The radius of curvature is half the diameter of a sphere from which a curved mirror or lens is derived.

Analogy

Picture yourself holding an enormous hula hoop. If you were to measure from your hand to any point along its circular edge, that distance would be equivalent to its radius. In this case, we're measuring from your hand to any point along the edge, but for lenses and mirrors, we measure from their centers to any point on the curved surface.

Related terms

Center of Curvature (C): The center point of a sphere from which a curved mirror or lens is derived.

Focal Length: The distance between the focal point and the lens or mirror.

Spherical Aberration: A type of optical distortion that occurs when light rays passing through different parts of a spherical lens or mirror do not converge at the same point.