Image capturing apparatus and control method therefor

An image capturing apparatus comprising:

• an image sensor that periodically outputs an image obtained by converting light entering through a diaphragm into an image signal;
• and
• one or more processors and/or circuitry which functions as:
• an acquisition unit that periodically acquires an aperture state of the diaphragm;
• a generator that generates a first indicator indicating a focus state of the image based on a value obtained by normalizing the focus state of the image based on the aperture state of the diaphragm at a time of exposure of the image;
• a controller that superimposes the image and an indicator indicating a focus state of the image, and displays a resultant image on a display device;
• a memory that stores the indicator displayed on the display device as a second indicator;
• and
• a selector that selects the first indicator in a case where the aperture state of the diaphragm at least at the time of exposure of the image or at a time of generating the first indicator by the generator is changing, and selects the second indicator in a case where the aperture state at these times is not changing,
• wherein the controller displays the indicator selected by the selector.