Iris? The iris consists of blades that perform what function?

• A. A device that stores color information for each frame.
• B. A component that adjusts the zoom.
• C. A system that manages autofocus.
• D. Blades that expand and contract, adjusting the aperture size.

Answer: (D)

The iris controls how much light hits the film or sensor by changing the aperture size. It’s made of overlapping blades that slide to open wider or close down, so the opening becomes larger or smaller. This not only adjusts exposure but also affects depth of field: a larger aperture lets in more light and gives a shallower depth of field, while a smaller aperture lets in less light and increases depth of field. The other descriptions don’t match what the iris does—storing color information, adjusting zoom, or managing autofocus aren’t functions of the iris.