This applet does not work in Netscape browser.
When parallel light rays enter a spherical lens, light aberration
occurs.
In order to focus light to a single point a system of lenses can be used.
Systems of lenses are used in cameras, telescopes, microscopes,
optical
digitizers, etc.
This applet demonstrates how light passes through a series of lenses.
Click in the white region on the left to change the amount of
light entering
the lens system.
Click on the arrows on the left to change the angle at which light enters
the system.
Drag each lens to change its position in the system.