An electromechanical scanner‐display system is described that as a scanner measures optical density in transparencies and as display device reconstructs the scanned image from digitally recorded optical density data. The instrument can accommodate image sizes up to 20×25 cm with maximum spatial resolution of 20 line pairs/mm. The optical density data are digitized into eight bits (256 levels) covering a range of 0–2.2 OD at a speed of 28 000 samples/sec. The display part of the system receives data digitized into 256 levels; out of these 95–105 can be distinguished at at output with statistical significance.