Choose how quickly focus responds when something passes between the subject and the camera in focus mode AF-C. Choose from values between 5 (Delayed) and 1 (Quick). The higher the value, the slower the response and the less likely you are to lose focus on your original subject. The lower the value, the quicker the response and the easier it is to shift focus to objects crossing your field of view. Note that 2 and 1 (Quick) are equivalent to 3 when auto-area AF is selected for AF-area mode.