Abstract: A light metering system which allows the user to select a color or gray scale reference for the system prior to operation of the apparatus (e.g. camera) with which the light metering system functions. The preselected reference chosen by the user takes into account values which will be recorded on an image recording element by the apparatus. The system is to be used on apparatus where shutter speed and diaphragm aperture settings are determined on the basis of the luminous power of the subject to be photographed taking into account the behavior of an element (e.g. film) on which the image is to be reproduced. The system includes a color selector mechanically associated with a color scale which, in turn, is directly related to a gray scale having a light intensity indicator. The light indicator is connected to a diaphragm aperture control device and to a shutter speed selector mechanism.