An imaging apparatus includes a lens optical system including a lens, a stop, and first through nth divided optical elements in which first through nth optical regions are defined, respectively, along a plane perpendicular to an optical axis and positioned to be point-symmetric with respect to the optical axis, an image sensor, and a microlens array guiding light that has passed through the first through nth optical regions to the first through nth pixels of the image sensor, respectively. At least three of s1, . . . , and Sn are mutually different and a relation of si≧si+1 is satisfied, where s1, . . . , and sn represent mean luminances of images obtained from the first through nth pixels, respectively. The first optical region and the nth optical region are positioned not to be point-symmetric to each other with respect to the optical axis.