Single Shot AF is standard and locks onto the subject until you take the picture. AL Focus is used when you can follow a moving object with the camera with the shutter button pressed half way. At the desired moment you take the photo. The moving object will be in focus. AL Servo shot AF is a combination of the two. | Single Shot AF is standard and locks onto the subject until you take the picture. AL Focus is used when you can follow a moving object with the camera with the shutter button pressed half way. At the desired moment you take the photo. The moving object will be in focus. AL Servo shot AF is a combination of the two. |