An exposure control system for daylight and flash photography. In the flash mode with computer flash light device, the system accommodates for a variation in the otherwise fixed parameter of diaphragm aperture by taking into account the camera-to-subject distance. In one embodiment of the invention, the diaphragm value and the integrated flash light are varied with distance at equal rates to each other, reaching the maximum possible values simultaneously at a distance twice as long as that when the diaphragm is fixed. In another embodiment, these variables are increased one at a time, reaching the maximum value, after which the other is increased to effect an equivalent result.