This item is displayed only with lenses that support it. Selecting Enable allows the lens focus ring to be used for manual focus when the camera is in autofocus mode; this is known as “autofocus with manual override” (M/A). After pressing the shutter-release button halfway to focus, keep the button pressed halfway and adjust focus using the focus ring. To refocus using autofocus, lift your finger from the shutter-release button and then press it halfway again. To prevent the lens focus ring being used for manual focus when the camera is in autofocus mode, select Disable.