Production of contrast masks system - intermediate mask formed using half tone film and used to produce actual contrast mask

摘要

A system for production of contrast masks for manufacture of duplicates or colour recordings of existing colour transparencies uses a half-tone negative film to produce a masked image of the colour transparency and the contrast mask itself is drawn out on a pre-exposed half tone film using the intermediate mask so formed. The intermediate mask is so illuminated that all the image densities from white to the mid-tone region of the colour transparency have a photographic density of pref. 1.90 - 2.10. The working process is to a large extent standardised since once tested the exposure and developing times remain constant.