1. A multiple lens imaging apparatus comprising: a plurality of imaging unit for obtaining images by photography; and exposure setting unit for using an exposure value calculated from a result of photometric measurement according to a predetermined photometric method for predetermined main imaging unit among the plurality of imaging unit, to set exposure of the main imaging unit and sub-imaging unit other than the main imaging unit, wherein, in the case where an image or images obtained in photography with the sub-imaging unit by setting the exposure thereof according to the exposure value is/are saturated, the exposure setting unit designates any one of the sub-imaging unit having obtained the saturated image or images as new main imaging unit, and calculates a new exposure value based on a result of photometric measurement for the new main imaging unit according to a photometric method different from the predetermined photometric method.