Time for action — lighting with only the key light
The key light is your main light. To know how to use it in combination with other lights, it helps to see how the light appears all by itself:
Select Layer 1, and then press the Shift key while selecting Layer 4 so that the key light, the camera, and Sintel are visible.
Press F12. The image should look similar to the following image. Press Esc when you have finished looking at the image.
What just happened?
Now you see only the key light, which is to the left of the camera and at a high angle above the Sintel. The shadows are strong. You can see a highlight on her forehead and at the top of her chest as seen on the left side of the following screenshot. The purpose of the key light is to do the main lighting for the scene.
