In a camera system including an electronic flash apparatus, a main capacitor of the flash apparatus is charged for a predetermined time interval, in response to a preparatory operation such as a first stroke of a release button. During this time interval, operation of an automatic distance measuring device, an automatic exposure controlling device and an object luminance discriminating circuit is prevented. A warning device warns a photographer that the main capacitor is insufficiently charged. Several voltage detectors detect different voltage levels of the main capacitor and produce detection signals for inhibiting the operation of the warning device and/or preventing further charging of the main capacitor.