The numbers describing the size of the lens opening are called?

• A. Shutter speeds
• B. F-stops
• C. ISO settings
• D. Exposure values

Answer: (B)

F-stops describe the size of the lens opening. The aperture is the hole through which light enters the camera, and the f-stop (f-number) is the ratio that indicates how big that hole is relative to the lens’s focal length. A smaller f-number means a larger opening and more light; a larger f-number means a smaller opening and less light. This size directly affects exposure and depth of field, which is why photographers adjust f-stops to control brightness and how much of the scene is in focus. Other common terms relate to different parts of the exposure process: shutter speed deals with how long the sensor is exposed, ISO settings describe sensor sensitivity to light, and exposure values are a broader exposure metric. So the numbers describing the lens opening are f-stops.