Digital camera or device with a digital camera unit is controlled in a process in which light spectrum power distribution is detected by a detector that has a plurality of narrow-band photo-electric sensors at locations spaced apart on an image capture unit of a digital camera unit. Each sensor has a given sensitive bandwidth within the frequency range of visible light. The number of the sensitive bandwidths is N that is greater than 3. A signal indicative of the light spectrum power distribution as detected by the detector is produced.