What is the calibrated ring on the lens indicating the aperture setting called?

• A. Aperture
• B. ISO
• C. F-stop
• D. Shutter

Answer: (C)

The primary idea here is how lenses regulate light and depth of field through the aperture, which is shown on a scale called f-stop. The calibrated ring on the lens that indicates this setting is the F-stop (f-number) ring. Each mark corresponds to an aperture size: smaller numbers mean a larger opening, letting in more light and producing a shallower depth of field; larger numbers mean a smaller opening, letting in less light and producing a deeper depth of field. ISO and shutter are separate camera controls—ISO relates to sensor sensitivity, and shutter controls exposure time—not the aperture ring. So the ring that shows the aperture setting is called the F-stop.