Certified Professional Photographer (CPP) Practice Exam

The function of a gobo, which stands for "go between" or "gobo image", primarily involves manipulating light in creative ways. It is designed to create patterns of light and shadow, modify the direction of light, and block light from directly hitting a subject, thus creating controlled lighting effects in photography or stage design.

When considering luminescence, it refers to the brightness or intensity of light emitted from a source. Gobos do not inherently increase the overall brightness of a light source; instead, they focus or shape the light that is already emitted from that source. They achieve this effect through the various materials or designs used, which alter the projected light rather than amplifying its output. Hence, the statement about increasing luminescence does not align with the fundamental purpose of a gobo, making it the correct choice for this question.