An incident light attachment is an accessory for a handheld light meter that enables the device to measure the light falling directly on a subject, rather than the light reflected from it. Some light meters come with this attachment permanently integrated, while others use removable diffusers or domes.
Using an incident light attachment helps photographers achieve more accurate exposure readings, particularly in studio or controlled lighting setups. By measuring the exact illumination on the subject, this accessory allows for consistent results, proper tonal range, and better control over highlights and shadows in both still photography and cinematography.