1. An object detecting apparatus comprising: an image sensor for capturing a plurality of object images in time sequence; a first detection start signal generator for generating a signal to start detection of an object, included in a first area, of the object images captured by the image sensor; a first detector for detecting a characteristic of the object included in the first area in response to the signal from the first detection start signal generator; a second detector for detecting an object similar to the characteristic detected by the first detector, within a second area larger than the first area; a second detection start signal generator for generating a signal to start detection by the second detector; a detection end signal generator for generating a signal to end the detection by the second detector; and a controller for performing focusing for the object detected by the second detector in response to the signal from the detection end signal generator.