A camera system that enables to stabilize, when photographing by using a flash apparatus in a live view state, the time lag between pressing the release button and starting the imaging operation thereafter, and also enables to execute the photographing with the short time lag. Photometry is performed in first pre-light emission executed before main light emission of a flash apparatus. Photometry is performed in second pre-light emission executed between the first pre-light emission and the main light emission. shooting condition for the camera system in the second pre-light emission is set based on a photometric value in the first pre-light emission so that an output of the second photometry unit is within a predetermined range. An amount of the main light emission of the flash apparatus is determined based on the photometric value in the second pre-light emission.