1. A digital camera, comprising: a photometering unit that measures brightnesses of a plurality of areas of a photographic field by dividing the photographic field into the plurality of areas; a reference value calculation unit that calculates a first reference value to be used to determine exposure conditions for a photographing operation based upon photometering results provided by the photometering unit and also calculates a second reference value, different from the first reference value, to be used to set gradation conversion characteristics in conformance to which gradation correction is to be executed on a photographic image photographed based upon the photometering results; an exposure condition determining unit that determines the exposure conditions for the photographing operation based upon the first reference value; a gradation conversion characteristics setting unit that sets the gradation conversion characteristics based upon the second reference value; and an image processing unit that executes image processing including gradation conversion executed by using the gradation conversion characteristics on the photographic image obtained under the exposure conditions via an imaging unit.