Digital SLR Camera Basics

The area of the frame that the camera will use for autofocus is shown by focus points in the viewfinder. Photographers can choose where the camera will focus by choosing a focus point. The selection can be made by the photographer or left up to the camera. The setting that determines how the focus point is selected is called AF-area mode. If you are using a Nikon D5000 digital SLR camera, you can choose from auto-area AF, single-point AF, dynamic-area AF, and 3D tracking. These AF-area modes are described below.

		Single point		The photographer selects the focus point manually; the camera focuses on the subject in the selected focus point. Choose for stationary subjects.
		Dynamic area		The photographer selects the focus point manually as above, but if the subject briefly leaves the selected focus point, the camera will focus based on information on the subject from surrounding focus points. Choose for subjects that are moving unpredictably.
		Auto area		The camera detects the focus point containing the subject and focuses automatically.
		3D tracking (11 focus points)		The photographer selects the focus point manually; if the shutter-release button is kept pressed halfway after the camera has focused, the photographer can change the composition and the camera will automatically choose a new focus point as necessary to maintain focus on the selected subject.

The locations within the frame that the camera can use for autofocus are shown by focus points in the viewfinder. In single-point AF, dynamic-area AF, and 3D tracking, the photographer can choose the focus point manually.