An image pickup apparatus has a live view mode, and includes a computer configured to adjust an aperture value of an image pickup optical system so as to maintain constant a depth of field when a zoom position of the image pickup optical system is changed. In response to a signal indicative of an increase of the zoom position, the computer in the live view mode is configured to output a signal used to increase the aperture value and a signal used to increase a gain of the image pickup element, and to make the display unit display the image data with a changed zoom position, a changed aperture value, and a changed gain. In response to an instruction to obtain a still image, the computer is configured to obtain the still image with the changed zoom position, the changed aperture value, and the changed gain.