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What is True WDR or WDR in Security Cameras?

What is True WDR or WDR in Security Cameras?

Apr 05, 2022 Posted by: VICTOR LI

WDR has become more readily available in Security Cameras in the last couple of years. But you may ask, “What is True WDR (or WDR) and why do I need it?

Cameras needed light to generate an image. With too much light, the image was washed out, too little light and the image was too dark. If you had an environment with even lighting, the camera could adjust its iris opening size or its shutter speed to get the right amount of light. However, our offices and our homes have a wide range of lighting. The cameras had a tough challenge. If the camera restricted the amount of light it took in (to optimize for the bright areas) the lower light areas would be too dark. If it chose the opposite approach, optimizing for low light areas, the bright side would be washed out.

That's why the Wide Dynamic Range (WDR) technology came out for help. In a nutshell, it’s the ability to produce high quality images across a broad range of light levels. In other words, the light coming in from a window may be much more intense than the light by your coffee machine. True WDR cameras that work with a shutter speed technique and two images. The camera takes pictures of both areas and stitches them together, giving you a better-quality image. 

True WDR cameras make a big difference in environments that have varying light levels. It is important to be able to capture the image of someone’s face as they walk into a dimly lit office from the bright sunlight outdoors. A subject’s hairstyle, clothing and details around him are crucial when studying the video surveillance footage.

With higher levels of light versus lower levels, you want a high performing WDR. Unfortunately, light measurements are not standardized and it’s the discretion of each manufacturer to determine what measurement to use. The generally accepted unit to measure in surveillance is the decibel (e.g., 58dB, 113dB, etc…). The higher the number, the better. The generally accepted dB level for a camera to be considered True WDR is 120dB.