Reference: L2
Category: Light and Waves
Purpose: Demonstrates spherical and chromatic aberration.
Description: Spherical aberration: large plano-convex condenser lens, fitted with disk pierced with several concentric rings of holes. Focus image of a pinhole on opposite wall. Show (on a moveable screen) that different zones focus at different lengths. Show that spherical aberration is worse with convex side towards pinhole. If chromatic aberration at the same time is to be avoided, use a colour filter in front of the pinhole (yellow or orange for brightest results.) Remove mask from condenser lens, and show effect of using the whole lens.
