WDR (Wide Dynamic Range)
WDR (wide dynamic range) means a kind skill of ensuring camera recognize specific features of objects in strongly contrast. WDR camera is scores of times as dynamic range as traditional camera which has only 3:1 dynamic range. Natural light ray ranges from 120,000Lux to 0.00035Lux of night vision. As camera taking outside photos in room, indoor illumination is 100Lux and outdoor illumination is 10,000Lux, thus the illumination contrast is 10,000/100=100:1. This contrast is easily recognized by human eyes which can recognize max contrast of 1000:1. Nevertheless, 100:1 is impossible to recognize for traditional monitoring camera which can only recognize max contrast of 3:1. In such conditions, traditional camera has to adopt 1/60 second electronic shutter in order to gain the correct exposure. But if doing so, the image of outdoor objects will be covered by full-screen-white without others; or adopting 1/6000 second shutter for gaining perfecting exposure, but indoor image will be covered by full-screen-black.
