1. A camera, comprising: a first storage type line sensor that corresponds to a first focus detection area; a second storage type line sensor that corresponds to a second focus detection area, which is different from the first focus detection area; a focus detection unit that detects a focus adjustment state of a photographic optical system by using a signal output from at least one of the first storage type line sensor and the second storage type line sensor; a photometric sensor that acquires image information corresponding to an image of a photographic subject from each of a plurality of areas; an extraction unit that extracts a main photographic subject region corresponding to an area where a main subject exists from the image information acquired by the photometric sensor; and a control unit that judges whether the main photographic subject region is located on the first storage type line sensor or the second storage type line sensor, selects, in units of pixels, pixels of a range corresponding to the main photographic subject region in a line sensor that has been judged that the main photographic subject region is located thereupon, controls an accumulation time period of the first storage type line sensor and the second storage type line sensor by using values outputted from the pixels selected in the judged line sensor and not using values outputted from pixels not selected in the judged line sensor.