Which lighting method often creates silhouettes of security personnel while they patrol?

Floodlighting is the correct choice because it is designed to illuminate large areas with intense brightness, often creating stark contrasts between light and shadow. When security personnel patrol an area under floodlights, the strong illumination emanating from their position can cause them to appear as dark silhouettes against the bright backdrop. This visual effect occurs because the light source is positioned in such a way that it highlights the area around them while leaving them less visible, which can be a disadvantage in terms of tactical visibility and personal safety.

In contrast, ambient lighting provides a general illumination level that doesn’t create harsh contrasts or shadows, making it less likely to produce silhouettes. Task lighting is focused on specific areas or tasks rather than creating a broad illumination; thus, it does not contribute to shadowy outlines of individuals. Spotlighting, while it does highlight specific targets, generally does not result in silhouettes unless the light source is behind the individual. Therefore, floodlighting stands out as the method that most typically creates silhouettes of personnel while they patrol.