WDR - wide dynamic range. The WDR function is designed to improve the video surveillance picture where bright light enters the frame against a dark background, such as a window or entrance.

There are two main approaches to implement the WDR effect. The first is hardware. Its principle of operation is based on the processing of two frames of different exposures, followed by combining two frames into one with the highest quality areas balanced in brightness.

The second principle is software processing (like in Photoshop), a dark area is selected and lightened, a light area is darkened.

WDR is measured in decibels (dB) and indicates the compatibility ratio between the brightest and darkest parts of a camera's image. A clear image is obtained with a higher rate. However, not all manufacturers provide quantitative indicators of this characteristic.

Technology and equipment are getting cheaper. Soon wdr will be a standard feature in any camera. Today, the cost of such a camera is not so great.

When choosing models of video cameras for installing video surveillance, you must definitely take into account the wdr function so that you do not choose an expensive high-resolution camera, and as a result do not get what you expected.

A video camera with wdr improves the image of all small details - license plates, faces of drivers, pedestrians.

Where is it recommended to use the WDR function:

• Entrance group of premises with glass doors (airport, train station, business center, etc.);
• Near (opposite) entrance doors;
• Opposite the doors behind which the illumination is greater than in this room;
• Opposite windows;
• In the entrances of apartment buildings;
• In places with a simultaneous arrangement of dark and bright areas.
• At the entrance to parking lots with daylight in front of the entrance from the outside and low lighting inside;
• Outdoors, in places with direct light and deep shadows;
• Opposite places with glare surfaces - office buildings with mirrored glass or a large number of densely spaced windows;

Here is a comparison table of cameras from different manufacturers: