In illuminating the facility, the light had to be bright enough for sports events, yet capable of being controlled for other activities. If students use the indoor jogging trace, for example, the school wanted to be able to provide recreational lighting. In applications such as this, high vertical footcandles are needed so that players in a basketball game or volleyball competition can see the side of the ball as it approaches. Dark areas and shadows also must be eliminated. Areas directly beneath the fixtures were very bright, but beyond those circles of light, the space was dark and full of shadows.
Glare can also be a problem if the light is provided directly from one source.
Uplight, which is a form of indirect illumination, not only helps eliminate glare but promotes uniformity by reducing the contrast between the lighting source and the surrounding area. Without uplight, you may have an appropriate amount of light on the surfaces near the floor, but the ceiling will appear dark and cavernous. Two different lighting systems may provide the same quantity of horizontal illuminance at three feet above the floor, but a system with uplight will improve the luminance of the ceiling and vertical surfaces. The glass reflector provide illumination in every direction, so there are no hot spots. How the facility is used will also determine the light levels needed.