The present invention relates to the improvement of an exposure control device in a camera having a centralized control system that has a built-in control circuit such as a microprocessor etc. and employing a shutter wherein an optimum exposure is obtained in a way that the exposure is given to the film between the gradual opening of the shutter and the closing thereof and the correlation between the shutter apertures and their corresponding lapse of time form a triangle on the graph. If further relates to the improvement of the exposure control means for flash photographing in a camera employing aforesaid shutter and a built-in strobe flash light source.
