A method, medium, and apparatus for setting an exposure time is provided. The apparatus includes a section setting module which sets one or more luminance sections based on a luminance distribution of an input image, an image division module which divides the input image into two or more regions, a region classification module which classifies the regions into the luminance sections, and an exposure-time setting module which sets an exposure time for each of the regions with reference to a target luminance value, the target luminance value being set based on the results of the classification performed by the region classification module.