An image capture apparatus sets an amount of exposure on an image sensor based on luminance information on an object field, calculates an expected signal level value that is an expected value of luminance signal level that is expected to be output from the image sensor when the image sensor is exposed at the set amount of exposure, compares the expected signal level value with an actual signal level value that is an actual value of luminance signal level output from the image sensor when the image sensor is exposed at the set amount of exposure, and sets a gain based on a result of the comparison.