PURPOSE: To show spherical aberration in a spherical mirror.
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: (PIRA 6A20.24) See also Demonstration L3-24: OPTICAL BOARD - SPHERICAL AND PARABOLIC MIRRORS, which illustrates the focusing difference between spherical and parabolic concave mirrors.
EQUIPMENT: Optical board with spherical concave mirror, concave and convax lenses.
SETUP TIME: None.
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