Talk:Radius of curvature (optics)

Confusing
"surface has a center of curvature, the vertex, located on the optical axis. The distance from the vertex to the center of curvature is the radius of curvature of the surface." This sounds like the center of curvature is the vertex. Then how can the distance from said vertex to the center of curvature be anything but zero?

In fact, the vertex is at the geometric center of the mirror. The center of curvature is located along the optical axis, some distance from the vertex, which the optical axis also intersects. The radius of curvature is the radius of the sphere from which the mirror was cut. — Preceding unsigned comment added by 208.80.117.214 (talk) 00:31, 18 May 2018 (UTC)
 * The text had gotten mangled by a previous editor. I restored an earlier version of the text.--Srleffler (talk) 03:43, 18 May 2018 (UTC)