Definitions for "Back Light"
Illumination from behind the subject and opposite the camera.
A light source that illuminates a subject from behind, used to separate the subject from the background and give them depth and dimension. Back lights are often improperly applied or overlooked completely. Also a switch on some camcorders used to compensate exposure for situations where the brightest light is coming from behind the subject.
Used behind the subject and pointing toward the camera for separation