Linearity refers to the extent to which the output of a system or device is directly proportional to its input. In photography and imaging, this concept is often applied to sensors, scanners, and digital cameras, where linearity ensures that changes in light intensity are accurately reflected in the recorded image.
Understanding linearity is important for photographers and imaging professionals who require precise tonal reproduction, accurate colour capture, and consistent exposure results. High linearity ensures that highlights, midtones, and shadows are faithfully represented, which is critical for scientific imaging, product photography, and professional-quality digital prints.