Illumination apparatus, illumination system, and illumination apparatus control method

An illumination apparatus (10) includes a determination unit (14a) that determines whether or not the supply of power from the system power supply is performed. In addition, the illumination apparatus (10) includes a control unit (14b) that performs control such that power is supplied to the light source (19A, 19B) from the battery (13) based on setting information of the light source when the determination unit (14a) determines that the supply of power from the system power supply is not performed.