The depth of field (DOF) is the range within which the object can move away from or towards the camera without resulting in a blurred image. The depth of field depends on the adjusted lens aperture, the distance to the test object, the focal length and the pixel size of the camera
Depth of field is controlled by changing the aperture setting on your camera. Like your eye, a camera lens has an iris inside that can open or close to let in more or less light. You control the size of this hole, or aperture, by changing the aperture setting, which is measured using a scale of f-stops.
Three main factors that will affect how you control the depth of field of your images are: aperture (f-stop), distance from the subject to the camera, and focal length of the lens on your camera. Here are some explanations and answers to other common questions concerning depth of field.