A method for controlling a display apparatus, the method comprising, displaying, in a first mode, a first image based on received image data having first resolution on a display surface at a first display size corresponding to the first resolution, displaying, in a second mode, a second image based on the image data having second resolution smaller than the first resolution on the display surface at a second display size corresponding to the second resolution, converting, when the display apparatus accepts the operation of increasing the second display size in the second mode, the first resolution of image data to third resolution corresponding to the operation, displaying a third image based on the image data having the third resolution on the display surface.