An iris out is a technique for fading to black. It is used extensively in cartoons and animations. At the end of a cartoon short, the cartoon fades to black with a black background with a transparent circle that slowly closes to all black, similar to a pupil closing.

The effect is made by superimposing a mask or matte of sequentially smaller circular cutouts over the animation action. The effect is combined with the animation reel using an optical printer.