What controls the emission of light from a streetlight?

The emission of light from a streetlight is primarily controlled by reflectors, refractors, or diffusing globes, which play a crucial role in directing and modifying the light produced by the bulb. Reflectors are designed to bounce light in specific directions, enhancing efficiency by directing more light down onto the area that needs illumination. Refractors manipulate light through bending, which disperses it effectively and reduces glare for drivers and pedestrians. Diffusing globes help in spreading the light evenly around the fixture, ensuring a softer, more uniform illumination.

While switches and sensors do trigger the streetlight to turn on or off based on environmental conditions or time, they do not directly control the characteristics of the light emitted. Wiring and circuit design are essential for powering the light but do not influence how the light itself is emitted or its distribution. The type of bulb used is also vital as it determines the color temperature and efficiency of the light, but it is the combination of reflectors, refractors, and diffusing globes that truly shapes how that light is cast into the surrounding environment.