Abstract: A portable device including at least one luminescent element, a camera including an image sensor for activation to produce an electrical image signal representative of an image sensed by the image sensor, and a camera signal processor including a camera memory for storing the image signal for subsequent reproduction of the image, the device also including a luminescence controller for controlling a brightness of the luminescent element, the camera signal processor is also arranged to activate the image sensor intermittently to produce sample signals representative of ambient light during periods in which the image signal is not being stored in the camera memory, the luminescence controller being responsive to the sample signals to modulate progressively the brightness of the luminescent element as a function of a brightness of ambient light.