When using ground mounted flood lights to light up a flag, the following factors are important to consider:
- Wattage
- Light Distribution
- Setback Distance
- Fixture Spacing
- Aiming Height
Wattage
The wattage of lamp being used to in the flag lighting application is dependent on three factors--pole height, flag size, and surround light levels. The following chart shows the recommended wattage of Metal Halide lamps in flood lights for most flag lighting applications.
| Pole Height | Recommended Wattage |
| 20' | 175W Metal Halide |
| 25' | 175W Metal Halide |
| 30' | 175W Metal Halide |
| 35' | 175W Metal Halide |
| 40' | 175W Metal Halide |
| 50' | 250W Metal Halide |
| 60' | 400W Metal Halide |
Light Distribution
For flag pole fixtures, the best beam distribution pattern is a spot or narrow flood. These patterns would fall into NEMA Type II or Type III. Without using proper lighting distribution, visibility of light on the flag is lost.
Setback Distance
Flood lights are recommended to be setback 1/3 times the pole height
1/3 x 30 ft. = 10 ft. high
| Pole Height | Setback Distance |
| 20' | ~ 7 ft. |
| 25' | ~ 8 ft. |
| 30' | 10 ft. |
| 35' | ~ 12 ft. |
| 40' | ~ 13 ft. |
| 50' | ~ 17 ft. |
| 60' | 20 ft. |
Fixture Spacing
Flood lights should be spaced 120 degrees apart surrounding the flag fixture. Ideally, three fixtures are used to cover all wind directions, and provide optimal uniformity.
Aiming Height
Aim each flood light to the center of the flag or top of the pole.
Source: Lithonia Lighting