This is a demonstrative model for 2D spherical mirror ray tracing in Excel. It works in Excel 2003 at about 40 frames per second and in Excel 2007 at about 4 frames per second. You can start it in a hands-off demo mode by clicking the “Fully Automatic Demo” button and at any time you can hit the the “Demo Style” button to choose a flexible (pulsating) mirror or a rigid one. You can stop this mode by clicking either the Joystick chart or the “Fully Automatic Demo” button. You can enter a semi-manual demo mode by clicking the Joystick chart and you will adjust the position of the light source by moving the joystick with the mouse. In order to be correctly callibrated make sure to click the red dot in the middle of the joystick chart whenever you start the virtual joystick. To stop the joystick macro you can click anywhere on the joystick chart. You can choose a flexible or rigid mirror in this mode too. You can adjust the speed of the model too using the “Demo Speed” button. You can use the model in fully manual mode by typing in various parameters. If you mess things up just download the model again from the site.