1. A method for an operation of an electronic device, the method comprising: determining illuminance corresponding to a subject; automatically determining a capturing mode of an electronic device based on at least the illuminance; acquiring a first resulting image of the subject based on a first exposure time, if the capturing mode is a first capturing mode; and acquiring a plurality of images of the subject based on a second exposure time, if the capturing mode is a second capturing mode, and generating a second resulting image based on at least two images among the plurality of images, wherein the generating of the second resulting image based on the at least two images comprises synthesizing the at least two images, and wherein the synthesizing of the at least two images comprises: selecting a least blurred image as a reference image among the at least two images, arranging at least one remaining image with reference to the reference image, and correcting pixel values of the reference image based on pixel values of the at least one remaining image.