A small reflection of a light source in a subject's eyes, seen as a bright highlight in the pupil or iris. Its shape, size and position depend on the lighting. A window, a softbox or an umbrella each leave a different shape. Many portrait photographers place their lights to create catch lights, because they make the eyes look more alive.
In film, a small light placed near the camera for this purpose was nicknamed an "Obie", after the actress Merle Oberon. It was devised by her husband, the cinematographer Lucien Ballard.
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