What is aperture in photography?

• A. The distance from the camera to the subject.
• B. The name of a type of lens.
• C. Opening; hole; adjustable opening in a camera that limits the amount of light.
• D. A device that controls shutter speed.

Answer: (C)

Aperture is the opening in the camera lens through which light passes to reach the sensor. It is adjustable, and its size controls how much light gets in. A wider opening (lower f-number) lets in more light, making the image brighter and giving a shallow depth of field, so the background appears blurred. A smaller opening (higher f-number) lets in less light, making the image darker but increasing depth of field, so more of the scene stays in focus. This is one part of the exposure triangle, along with shutter speed and ISO. The other choices don’t fit because distance to the subject relates to focus and composition, the lens name describes the type of lens, and a device that controls shutter speed is the shutter.