Regulating filtering and exposure of photographic printer - using TV CRT display with electronic controls between light house and negative film or diapositive

摘要

The image projected onto the print plane (12) is monitored by a CCTV camera (14) linked to a processor (16,17) and to a monitor (15). The processor corrects for colour, contrast and spatial illumination by controlling a display screen (5) positioned in the optic path. An alternative solution has the light source replaced by a CRT screen with spatially variable illumination. The processor operates negatively to counter the illumination distribution, with controlled gain. The operator varies the processor while watching the monitor until optimum picture quality is obtained. ADVANTAGE - Direct correction of otherwise difficult negatives or slides; simple to operate.