Time for action – adjusting the falloff

Now that the scene is set, check out how much you can vary the light without ever changing the energy that the light emits:

1. In the Lamp subpanel of the Properties window, click on the Sun button.
2. Press F12. No falloff will occur; sunlight does not get dimmer; only spotlights, point lights, and area lights get dimmer.
3. Click on the Spot button in the Lamp subpanel.
4. Press F12.
5. In the Lamp subpanel, change the Distance option of Falloff from 25 to 12.
6. Press F12.
7. In the Lamp subpanel, set the Distance option of Falloff to 50.
8. Press F12.
9. In the Lamp subpanel, set the Distance option of Falloff to 100.
10. Press F12. Press Esc when you have finished looking at the image. Compare what you have seen in the three renders, as shown in the following screenshot:
    

What just happened?

This section brings up a good question. If light can travel distances so far that it takes billions of years to get there, why does light get dimmer just crossing a room? Shouldn't it...