A detecting apparatus for detecting a focusing condition or a distance from a subject, and a camera having the detecting apparatus. The apparatus includes: image taking lenses which make respective subject images on respectively individual positions; area photo sensor, which are of the charge accumulation type, arranged on the respective positions focused by the lenses; and at least one of brightness monitor, arranged across a detecting area of at least one of the area photo acceptance units, for controlling charge accumulating time of the area photo acceptance units.