from the image pickup apparatus 1 photographing an object until blurring the photographed image in a predetermined way that is until generating of an image of which depth of field is shallow and displaying the generated image if a photographing start button not illustrated is pressed step s 201 starts in step s 201 the exposure control unit 104 and the distance measurement control unit 105 controls exposure and focusing and determines the photographing conditions then the image sensor 102 converts the object image which was formed via the optical system 100 into an electric signal and generates an analog signal according to the brightness of the object then the analog signal generated by the image sensor 102 is formed into a digital image by the image forming circuit 103 and is recorded in the frame memory 109 the image acquired in step s 201 is a focused image in step s 202 the object is photographed in the same manner under different photographing conditions including focusing position aperture stop and focal distance so that the degree of blurring of the object is different from the image photographed in step s 201 the photographing conditions may be changed in any way only if an image of the same object of which degree of blurring is different can be acquired the photographed image is recorded in the frame memory 109 in the same manner the image acquired in step s 202 is the defocused image it.