A photographic color effects lighting filter system made up of a series of lighting filters which are designed to be placed in front of one or more lighting sources. The lighting color effects filter series is made up of groups of filters wherein each of the filter groups is composed of a plurality of...http://www.google.com.hk/patents/US6259572?utm_source=gb-gplus-share專利 US6259572 - Photographic color effects lighting filter system
