When using ground mounted flood lights to light up flags, the most important factors to take into consideration are:
- Light Distribution
- Setback Distance
- Spacing Between Floodlights
- Aiming Point
Lamp wattage should be carefully considered when choosing the right flood light fixture, depending on height of the pole, flag size, and surrounding light levels. Take a look at the chart below for some recommended wattages for floodlights using Metal Halide lamps.
|Pole Height||Recommended Wattage|
|20’||175 watt Metal Halide|
|25’||175 watt Metal Halide|
|30’||175 watt Metal Halide|
|35’||175 watt Metal Halide|
|40’||175 watt Metal Halide|
|50’||250 watt Metal Halide|
|60’||400 watt Metal Halide|
For flag lighting, the desired distribution pattern is typically a narrow or “spot” pattern. This beam pattern is especially important in illuminating the flag to be visible.
The distance a floodlight should be setback from the flag is 1/3 times the pole height.
Setback Distance = 1/3 * Pole Height
Example: If a pole is 30 feet tall, the floodlight should be set 10 feet away from the pole.
Spacing Between Floodlights
Ideally, three floodlight fixtures should be used to cover all directions the wind may wave the flag, and uniformly illuminate the flag. Each of the three floodlights should be spaced 120° apart.
The recommended aiming point of each floodlight is the center of the flag or the top of the pole.