Abstract: A charging device (1) for a camera flash includes a digital signal processor (10) providing a pulse width modulation signal and receiving a feedback signal, a voltage boosting circuit (20) electrically connected with the digital signal processor for outputting an induced current under the control of the pulse width modulation signal, a flash capacitor (40), and a charging circuit (30) electrically connected with the voltage boosting circuit and the flash capacitor for charging the flash capacitor by the induced current. The charging circuit includes a protection circuit (310) for protecting the flash capacitor and a feedback circuit (320) for outputting the feedback signal to the digital signal processor.

Abstract: A camera system with function of automatically coordinating flash intensity includes a lens, an image sensor, a focus system, a focus sensor and a control unit. The lens controls light amount that entrance into camera. The focusing system drives the lens to focus thereby forming a clear image on the image sensor. The focus sensor senses first step information of the focusing system during the focusing process, and sending the information to a control unit. The control unit transforms the result of the focusing system to a distance that the object apart from the camera, and configures out the guide number with the aperture number thereby calculating the flash intensity. The present camera systems may measure the distance that the objects apart from the camera, and low down the cost and power consumption. The camera systems may also precisely control the flash intensity thereby coordinating the exposure effect.