What does incident light measure in photography?

Incident light refers to the measurement of light that directly strikes the subject being photographed. This measurement is crucial because it determines the exposure settings necessary to correctly capture the lighting conditions. By measuring the light falling on the subject, photographers can achieve proper exposure that reveals the details and textures in the photograph without overexposing or underexposing the image.

While reflected light, which often bounces off the subject or surrounding surfaces, can also provide valuable information, it does not give a complete or accurate picture of how the scene will actually be captured. Instead, incident light directly relates to the light source illuminating the subject, making it essential for understanding how to best set the camera's aperture, shutter speed, and ISO settings.

Additionally, monitoring ambient light can be helpful for broader scene considerations, but it does not specifically measure the light that directly illuminates a subject. For achieving accurate exposure in photography, assessing incident light is key, as it responds directly to the primary illumination affecting the subject.