Method for making a light intensity correction filter
Abstract
Abstract TO MAKE A LIGHT INTENSITY CORRECTION FILTER FOR A LIGHTHOUSE: (1) PREPARE A TRANSMISSION PATTERN WHICH, WHEN PLACED IN A PREDETERMINED POSITION ADJACENT AND ELEMENT OF THE LENS ASSEMBLY OF THE LIGHTHOUSE, COMPRNSATES FOR NONUNIFORMITIES IN BRIGHTNESS DUE TO ASYMMETRICAL REFRACTION OF LIGHT PROJECTED THROUGH THE LENS ASSEMBLY; (2) PREPARE A NEGATIVE IMAGE OF THE TRANSMISSION PATTERN; (3) POSITION IS A LIGHTHOUSE A LIGHT SOURCE, AT LEAST ONE OPTICAL ELEMENT OF THE LENS ASSEMBLY, WHICH ELEMENT CARRIES ON ONE SURFACE THEREOF A LAYER OF A PHOTOSENSITIVE COMPOSITION CONTAINING LIGHT ATTENUATION MATERIAL, AND THE NEGATIVE IMAGE; (4) PROJECT LIGHT FROM THE LIGHT SOURCE INCIDENT UPON THE COATING OF PHOTOSENSITIVE COMPOSITION; (5) AND THEN DEVELOP THE EXPOSED COATING TO PRODUCE THE FILTER.
Inventors
- 👤 Frank Rowland Ragland Jr
Bibliographic Details
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