Abstract: A method and apparatus is described for determining the time intensity integral of the exposure of a negative in additive primary colors onto photographic paper. A plurality of discrete areas of a negative are scanned and the light transmitted through these areas is directed onto photosensitive devices each appropriately filtered to be responsive to a different one of the primary additive colors. The electric signals derived from the photoelectric device are applied to fulcrum circuits, one for each of the additive colors; the fulcrum circuits each form an analog voltage linearly corresponding in their respective colors to the fraction of the total area of the negative which has a transmissivity greater than the mean transmissivity of the whole. The analog voltages thus derived, one for each of the primary colors, are applied to control circuits that produce electrical signals to terminate the exposure in the corresponding primary color in accordance with the amplitude of the analog voltage.