WDR stands for Wide Dynamic Range (WDR). There are mainly two types of surveillance cameras.

(1) True-WDR cameras – which use hardware shutter-speed technique.

(2) Digital WDR (DWDR) cameras – which use software compensation technique.

120dB True WDR cameras work by capturing two images with different exposures to light and merging them into a third one, and therefore work more intensely but also more efficiently, whereas the digital WDR cameras work only with one image to make a digital exposure compensation.

Generally, the higher the dB value, the better. The generally accepted dB level for a camera to be considered True WDR is 120dB. dB measures the ratio of the brightest and darkest area in the picture that can be captured by the camera sensor.