This applet traces light rays through a set of lenses using geometric optics.
The applet has three modes of control:
- Buttons allow a new lens to be inserted or the currectly selected lens to be removed. The viewing area can be made larger or smaller.
- The scrollers allow the focal length and diameter of the currently selected lens to be altered.
- The mouse can be used to select a lens by a single click or to move the position of a lens by clicking and dragging on it. The current viewing area can be moved by clicking and dragging anywhere else in the view. A single cleck away from a lens activates or deactivates a cursor.