Improvement in Illumination Efficiency of Motion Picture Printers
Motion picture printers now in common use were designed to be operated at a moderate running speed with a single type of film of such emulsion speed that ample exposures were obtained by the use of low-wattage tungsten lamps. Recently the use of a variety of fine-grain films has made necessary greater exposure intensities. Tungsten lamps of higher wattage or mercury-vapor lamps have satisfied, the need for increased light intensity in some cases, but have not been found practicable for use in others. — Greater optical efficiency is needed in many of the printers. This can be obtained by the use of light-collecting systems involving the use of either condensers or reflectors. Some special problems are introduced by the peculiarities of the mechanical arrangements of the printers and sometimes by the requirement of uniformity of illumination, both at the printing aperture and at the light-change aperture. — Examples showing the application of condenser and reflector systems to 2 typical printers are given with a detailed description of the optical design as well as of the mechanical problems encountered. Data are given on the increase in illumination efficiency obtainable in practice.
- Print ISSN
- 0097-5834
- Published
- 1944-05
- Content type
- Original Research
- DOI
- 10.5594/J08446