Certified Professional Photographer (CPP) Practice Exam

What type of triggers activate a light when they detect another flash going off?

1. photosensitive

2. mechanical

3. ultrasonic

4. infrared

The correct answer is: photosensitive

Photosensitive triggers are specifically designed to activate a light when they detect the illumination caused by another flash. These triggers utilize a light-sensitive component that reacts to the rapid increase in light intensity from a flash burst. When a flash goes off, the photosensitive trigger detects the light and sends a signal to activate the connected light source. In contrast, mechanical triggers involve physical movement or pressure to activate lighting. Ultrasonic triggers utilize sound waves, which are not applicable in this context since they rely on auditory signals rather than visual cues. Infrared triggers work by detecting heat or infrared radiation, which also does not suit the requirement of responding to a flash of light. Thus, photosensitive triggers are the only option that directly responds to the flash of another light source, making it the correct choice.