An image pickup system includes a light source apparatus and a light-source control section performing first control for setting a duty width and perform second control for, after the duty width is set to a minimum duty width by the first control, changing supply timing of the illumination light not to supply the illumination light in a period other than the period where the light amount control by the PWM is permitted and to supply, in the period where the light amount control by the PWM is permitted, light having a light amount integrated value equal to a light amount integrated value supplied in the period other than the period where the light amount control by the PWM is permitted, and an image pickup apparatus, where data representing a driving current value after the change of the supply timing and a value of the pulse width is stored.
