What is the adjustable lens opening mechanism on a camera called?

What is the adjustable lens opening mechanism on a camera called?

• A. Shutter
• B. Aperture
• C. Iris
• D. Focus Ring

Answer: (C)

The iris is the mechanism that adjusts the lens opening. It’s a set of blades that open wider or close tighter to change the size of the aperture—the actual hole through which light enters the lens. The aperture is the size of that opening and is what you adjust to control exposure and depth of field, but the device that makes that adjustment is the iris diaphragm. The shutter governs how long light hits the sensor, and the focus ring alters focus distance. So the iris is the correct term for the adjustable mechanism that controls the opening.

The iris is the mechanism that adjusts the lens opening. It’s a set of blades that open wider or close tighter to change the size of the aperture—the actual hole through which light enters the lens. The aperture is the size of that opening and is what you adjust to control exposure and depth of field, but the device that makes that adjustment is the iris diaphragm. The shutter governs how long light hits the sensor, and the focus ring alters focus distance. So the iris is the correct term for the adjustable mechanism that controls the opening.