Digital Photography Using a High-Transmittance Electro-Optical Iris

In this paper, a tunable electro-optical iris with high transmittance, based on polymer dispersed liquid crystal (PDLC) material, and a relevant image enhancement method are combined for digital photography. Our device is controllable by adjusting the voltage and no mechanical and moving components are required so as to improve the stability. The experiments show that transmittance of light throughput is tunable from nearly 0% to 77% by gradually increasing driving voltage. The digital camera system using our PDLC iris can capture the high-contrast image in real-scene photography. To further improve the image quality, we develop an iterative image enhancement method that is able to improve the signal-to-noise ratio by ~10 times and increase the image brightness simultaneously. The combination of the PDLC electro-optical device and a variant of the enhancement algorithm can also have the potential to be applied in optical imaging and sensing.