NALMCO Certified Apprentice Lighting Technician (CALT) Practice Exam

Which factor may affect the overall uniformity of light in a LED lighting system?

1. System voltage

2. Dimming control system

3. Temperature of the area being illuminated

4. Luminaire optics

The correct answer is: Luminaire optics

The overall uniformity of light in an LED lighting system is significantly influenced by luminaire optics. Luminaire optics play a critical role in how light is distributed in a space. They include the design elements such as lenses, reflectors, and diffusers that determine how the light emitted from the LED sources is directed, spread, or shaped. Effective optical design can enhance the uniformity of illumination by ensuring that light is evenly distributed across the desired area. For example, a well-designed lens might focus light more precisely, reducing hotspots or dark areas, thus contributing to a more even light output. If the optics are poorly designed, it can lead to uneven light distribution, which can create areas of excessive brightness and regions that are inadequately lit. Conversely, while other factors like system voltage, dimming control systems, and temperature can impact the performance and efficiency of LED fixtures, they do not have the same direct impact on how uniformly the light is spread in a space as the luminaire optics.