Backlight shining in through entry doors, or bright artificial light sources make using video surveillance cameras difficult in stores. However, even the starter models from ABUS feature the efficient WDR technology which also provides perfectly exposed images in scenes with high levels of light contrast.
Wide Dynamic Range balances out strong differences in contrast and brightness. The principle: Each image is recorded several times with varying exposure times, so that one part of the image is always optimally exposed. For example, a dark background is optimally lit if exposed for a long time, but a bright foreground can only be identified if the exposure time is short. The camera automatically selects the best sections of the image and then assembles the overall image digitally.
Cameras with WDR technology are often used in the foyers of buildings, where the camera is used to record all persons entering. Cameras without WDR technology often display persons entering far too darkly, because the camera adjustment is set for the bright sunlight shining from behind and the faces of the people are obscured by their own shadows. Cameras with a WDR function can handle this difference in contrast significantly better, i.e. the areas which are too bright are darkened and the dark areas brightened. This allows the faces of people to be identified better.