Optical Board - Spherical Aberration In Concave Mirror

Purpose

To show spherical aberration in a spherical mirror.

Equipment

Optical board with spherical concave mirror, concave and convax lenses.

Images

l3-13

Description

Spherical aberration can be shown using a number of rays to show how they focus. The number and spacing of rays can be changed by choice of slit baffle and changing the position of the baffle. A baffle with pairs of rays equidistant from the optical axis of different colors can be used to emphasize the difference between pairs of rays. ◙◙Using a rectangular open baffle the caustic can be illustrated, as in the photograph at the right above.

References

Richard Ditteon, A New Sign Convention for Geometrical Optics, TPT 31, 38-40 (1993).