for education and personal use. h|jz

Thin Lens and Mirror Demonstration

With thanks to Fu-Kwun Hwang.

  1. A lens is outlined in light gray..
  2. A mirror is represented by a thick black line.
  3. The object is represented as a black arrow.
  4. A real image is represented as a blue arrow and blue lines represent the real light ray paths.
  5. A virtual image is represented as a light arrow and green lines represent the virtual light ray paths.
  6. The +/- toggle button swtiches between a converging and diverging lens or a convex or concave mirror.
  7. You can drag and drop the object along the horizontal axis to change the object distance.
  8. You can change the focus by drag and drop on the top or bottom of the lens or mirror.
  9. Small red tick marks show the center of the lens or mirror and the distances f and 2*f.
  10. You can open two windows to compare different cases.
  11. You can manually change each of the parameters inside the textfields and see the results.
  12. To quit the demo click the Close bar.


Click the Start button to begin.