WDR (Wide Dynamic Range) combines the spaces of bright lights with the spaces of shadows that are in the same shot, to create a balance in the final image. This is possible by doing full exposure metering (highlights, tones, colors, depth of field, objects, etc.) and adding light detail on the gloomiest surfaces, and subtracting luminescence from the brightest areas. Such modification can improve up to 800% of the image quality compared to that of a camera without WDR.
What Is the Function of the WDR?
Wide Dynamic Range (WDR) refers to the ratio between the largest and smallest measurable amounts of something.
In the case of video surveillance, the dynamic range measures the relationship between the elements that are lighter or with greater illumination and darker or less incidence of illumination in the image.
WDR technology is excellent for high-contrast scenes, balancing brightness and shadow areas simultaneously so the image doesn’t appear washed out or too dark.Read More
Decibels (dB) are the value by which dynamic range is measured; IHS defines WDR at 60 dB or more, although it’s not uncommon to see WDR cameras with capabilities of 120 dB or more.
However, it should be noted that each manufacturer has its own method for determining the dB of a camera.
Therefore, when comparing product data sheets, it is possible that a camera with a lower ratio will outperform a competitor with a higher dB ratio.
How Does WDR Work?
Security cameras with WDR technology (eg Dahua HDCVI 6.0 PLUS) use Digital WDR (DWDR) or True WDR.
True WDR uses image sensors and a digital signal processor (DSP) to deliver uniform illumination across all areas of an image.
A True WDR-enabled CCTV camera has sensors that take two scans of each video frame.
The first, at low speed (to capture more light), displays the image in normal lighting conditions.
The second scan is taken at a high speed to capture less light overall and get an image with a strong backlight.
The DSP combines the two scans to form a single, balanced, well-lit image.
Benefits of WDR
- Neutralization of reflections and glare – While most indoor surveillance cameras struggle to capture images outside of glass windows and doors, WDR cameras can mitigate problems such as glare from glass, vehicles, and bodies of water, making video images seamless and clearer. Fluorescent lighting and car headlights are also no problem.
- Restoration of natural colors – While traditional CCTV cameras tend to distort or wash out colors, WDR cameras can capture the natural color of objects.
- Less heavy storage – In addition to having a more accurate color balance, WDR cameras also reduce image noise, allowing the captured image to be smaller. This reduced file size saves you storage costs, making WDR cameras more cost-effective in the long run.
Why Do I Need a Camera with WDR?
The use of cameras with WDR is the ideal solution for spaces that require high-quality (video) monitoring, without loss of detail, and that are exposed to changes or extreme light conditions. For example, spaces where the camera will be looking from the inside to the outside of a door that is constantly opened, that has to be seen through glass doors, stained glass windows, gates, windows with excessive light, and/or areas where there are permanent or momentary reflections.