A Sensitometer and Automatic Recording Densitometer for Colour Films

As the requirements made upon photographic material become more exacting, and accordingly, the manufacturing and processing tolerances more restricted, it becomes necessary to control every step accurately, from the impact of light on the sensitive emulsion to the finished image. The measurement of the different characteristics of an emulsion and the study of the connexion between its various properties, such as sensitivity, exposure range, contrast, resolving power, fog, etc. has been customary for black-and-white material for a long time. The development and improvement of the colour film make sensitometric control still more imperative, owing to the greater complexity of this material.