PURPOSE: To calculate proper exposure data to an object regardless of the position of the object in a picture at the time of taking the picture of the object against the light by calculating the final photometric frame for deciding exposure in such a way that a photographing picture is divided into matrix-like areas and each area is grouped to rectangular forms, and then, the groups are successively reduced while the picture is oriented to a principal object.

CONSTITUTION: Upon catching an object in a photographing picture, the whole photographing picture is first set as a reference photometric frame and a reduced photometric frame against the reference photometric frame is moved by using the four corners of the reference frame as references. After the reduced photometric frame is positioned to the place where the average luminance value of the reduced photometric frame becomes the minimum, the next reduced photometric frame which is further reduced in size is positioned by using the first-mentioned reduced frame as a reference photometric frame. By repeating the above-mentioned operations, plural reduced photometric frames are set. When the difference between the maximum luminance value of the plural reduced photometric frames and the maximum luminance value obtained when the whole photographing picture is considered as a photometric frame exceeds a fixed value, the exposure is decided in accordance with the luminance data of the reduced photometric frames. Therefore, at the time of taking a picture containing a high-luminance object against the light, proper exposure can be calculated even if the object stays at any place in the picture.