Spherical aberration is a description of the fact that a spherical mirror has a focal length (call it f_f) for light striking it far from the central axis that differs from the focal length (call it f_c) for light striking it close to the central axis. By taking the "limiting" case of a hemisphere it becomes clear that A) f_f f_c for the outer rays not "far" from the central axis, and f_f f_c for the outer rays not "far" from as well as for outer rays farther from the central axis.

Question

Spherical aberration is a description of the fact that a spherical mirror has a focal length (call it f_f) for light striking it far from the central axis that differs from the focal length (call it f_c) for light striking it close to the central axis. By taking the "limiting" case of a hemisphere it becomes clear that A) f_f < f_c for the outer rays not "far" from as well as for outer rays farther from the central axis. B) f_f < f_c for the outer rays not "far" from the central axis, and f_f > f_c for outer rays farther from the central axis. C) f_f > f_c for the outer rays not "far" from the central axis, and f_f < f_c for outer rays farther from the central axis. D) f_f > f_c for the outer rays not "far" from as well as for outer rays farther from the central axis.

Quizplus · Accepted Answer

In spherical aberration, rays striking the mirror far from the central axis (outer rays) focus closer to the mirror than rays near the axis, meaning f_f < f_c.

Spherical Aberration Is a Description of the Fact That a Spherical