Alternatives for the specifications of a color negative film target for input scanner calibration

Color negative films are designed to be intermediate records of photographed objects rather than the final reproduction. Their light absorption serves only to attenuate the printing exposure of another photographic material. They are low gamma, nonviewable films designed to be printed onto high gamma print materials, and the spectral sensitivities of these print materials differ significantly from the human visual system. Input scanners optimized for viewable transmission and reflection materials are not necessarily optimized for color negative films. Their wide exposure latitude and good signal/noise performance result in color negative films being good image capture media. Images having excellent color reproduction, tone scale and image structure characteristics can be extracted from scans of color negative films, but the complexity of recovering optimum pictorial results has resulted in these films being somewhat of an enigma in the desktop publishing and graphic arts arena. The IT8 SC4 committee is in the initial stages of appraising the necessity and considering the specification and design of an input target that would permit calibrated scans to be obtained from color negative films. This paper presents an overview of the negative-positive system and summarizes several specification schemes which could be used as a basis for the design of an IT8 color negative film input calibration target.