A Brief Survey of the Physics and Technology of the Berthon-Siemens Color Process

An analysis is made of the advantages and limitations of the lenticular color-film system over that of the screen-film method as well as processes using three separate images. Exposure of lenticular films requires a perfect system of objectives with uniform optical filter position. Entirely new types of negative emulsions of high resolving power were devised to overcome irradiation effects. — Methods of printing lenticular films are described. Objectives of small aperture were developed to offset color fringing resulting when large-aperture objectives were used. The three separation images are registered by a mirror system. — New arc lamps of very high efficiency are described for use in projection. They operate with horizontally arranged square carbons and magnetic stabilization. The luminous gas portion extends in front of the positive carbon and can radiate laterally without obstruction. With 60 amperes the intrinsic brilliance in the crater was found to be 800 candles per sq. mm. — A further increase of screen brightness was realized by the use of a special projection screen which confined the reflected light within the needed angle. Metal sheets are used into which one million small concave mirrors are rolled per square meter. On the basis of conditions prevailing in the German theaters, an increase of screen brightness by a factor of 3 can be attained with the use of the new screen.

Print ISSN

0097-5834

Published

1937-05

Content type

Original Research

DOI

10.5594/J08537