Digital photographing apparatus, method of controlling the same, and computer readable storage medium

A digital photographing apparatus, a method of controlling the same, and a computer readable storage medium, the method including obtaining a first image captured from an optical signal received via a first optical system; obtaining a second image captured from an optical signal received via a second optical system; calculating a first histogram from the first image, where the first histogram represents a frequency distribution according to values of pixels of the first image; calculating a second histogram from the second image, where the second histogram represents a frequency distribution according to values of pixels of the second image; comparing the first histogram and the second histogram with each other; and determining whether an obstacle is present on at least one of the first and second optical systems, based on the result of comparison.