An incident light reading is the measurement of light falling directly on a subject, taken using a handheld light meter. To take this reading, the meter is placed near the subject and pointed toward the primary light source, capturing the amount of illumination hitting the scene rather than the light reflected from it.
Incident light readings allow photographers to achieve accurate exposure settings, especially in studio or controlled lighting conditions. By understanding and using these readings, photographers can maintain consistent brightness, balance shadows and highlights, and produce images with precise tonal quality.