The default light shines from over the right shoulder of the viewer. The following controls, accessed from the <Shift-L> key, can be used to change the direction and intensity.

Figure 15. Frozen Direction

Normally the light rotates with the viewer so its always over the right shoulder. By freezing/fixing the light direction with <Shift-L> <f> you can get it to shine from any angle. Type <Shift-L> <f> again to unfreeze the direction.

Figure 16. Gamma - 0.5 - 1.0 - 2.0

Some display monitors can be overly light or dark. If your graphics card doesn't support some means of changing the display gamma, it can be hard to see surface detail in dark or flared out areas. In these situations you can change the gamma of the shading with <Shift-L> <g>; less than one is lighter, greater than one is darker. This would be considered as a last resort solution because shading with a gamma not equal to 1 is significantly slower.

Figure 17. Intensity - 0.5 - 1.0 - 2.0

Use <Shift-L> <i> to change the light intensity. This doesn't affect the rendering speed, so might be more appropriate to improving shading levels than changing the gamma. In some circumstances a combination of gamma and intensity might be needed (e.g. many laptop displays).

Figure 18. Swap Side

As described, the default light shines from over the right shoulder. Type <Shift-L> <s> to swap that to over the left shoulder.