What is Wide Dynamic Range (WDR) in IP Cameras?

Ever wondered why some security camera footage looks washed out or too dark to make out details? It's all about the dynamic range – the balance between light and dark areas in an image. Understanding what is wide dynamic range becomes essential when discussing camera performance. With WDR technology, cameras can effectively manage contrasting light, ensuring critical details are captured in all lighting conditions. Let's dive into the world of WDR and how it revolutionizes security surveillance.

What Is Wide Dynamic Range?

Dynamic range is a concept that refers to the ratio between the largest and smallest possible values that can be measured. In the realm of video surveillance, the dynamic range stands for the contrast ratio between the darkest and brightest color tones that a camera can capture in a single exposure. The purpose of WDR (Wide Dynamic Range) is to masterfully balance these extremes in high-contrast environments, effectively ensuring that bright areas are not washed out and dark areas retain detail, thus avoiding under- or overexposure.

The measure of a camera’s dynamic range is expressed in decibels (dB), with the industry benchmark set by IHS Markit defining WDR as having a range of 60 dB or more. However, it is not rare to encounter WDR cameras that offer dynamic ranges of 120 dB or even greater.

The comparison of the two images below illustrates the effectiveness of WDR technology in surveillance cameras. Without WDR, the camera's image is overexposed by the light from the window, obscuring the exterior view and leaving the room's interior too dark. With WDR enabled, both the bright outdoor scenery and the interior details of the conference room are captured with balanced exposure, ensuring clear visibility of both areas in the same frame.

How Does WDR Work?

There are two processors for the WDR technology, a light image processor and a dark image processor, and by combining the two processors, you can get a clear and high-quality image.

With WDR technology, one PoE IP camera lens allows more light in some areas of the image and less light in other brighter areas through different shutter speeds. The sensor's exposure to light it receives from outside is controlled to obtain a balanced WDR image.

• In lighter areas, the shutter speed of the camera lens is higher, so the sensor is exposed to light for less time.

• In darker areas, the shutter speed is relatively slower, it takes longer for the sensor to capture more light.

• By combining both images, a final higher-quality image is obtained.

True WDR vs DWDR

True WDR (Wide Dynamic Range) and DWDR (Digital Wide Dynamic Range) are two technologies implemented in cameras to manage high-contrast lighting conditions.

True WDR utilizes a combination of hardware and software to capture multiple frames at different exposure levels almost simultaneously. It then combines these frames to produce a single image with balanced exposure, preserving detail in both the brightest highlights and deepest shadows.

DWDR, on the other hand, manipulates a single image through software to brighten shadows and tone down highlights. It's less effective than True WDR but is a more cost-effective solution suitable for less challenging lighting situations.

WDR vs HDR

WDR (Wide Dynamic Range) and HDR (High Dynamic Range) are two distinct image processing techniques that aim to enhance the performance of image capture in high-contrast scenes. Understanding the differences between WDR and HDR is essential for selecting the right surveillance technology to meet diverse environmental and quality requirements.

By comparing HDR and WDR, we recommend WDR technology for security cameras for the following reasons.

• High-Speed Processing: With the support of high-speed DSP, WDR can deal well with dynamic images or videos.

• Adjustable Exposure: The WDR can output one set of two or four frames with different exposure times, the gain can also be set separately for each frame in addition to the exposure time.

• Backlight Compensation: WDR allows imaging systems to correct for the intense backlight surrounding subjects and thus enhances the ability to distinguish features and shapes on the subject.

• Better Low-Light Imaging: WDR technology can capture the images in dark places as well as illuminate them hence ensuring security even with low power or no power at all.

• Sharp Details: Compared to HDR, the image produced by WDR technology is exceptionally sharp with more details.

• Cost-Effective: A WDR camera is cheaper in installation cost and purchase price as compared to an HDR camera.

Where to Use WDR Cameras?

WDR cameras are commonly used in environments with challenging lighting conditions, such as areas with high contrast between bright and dark areas. Some common applications include:

Entrance

The most common place for WDR cameras is monitoring building entrances. Whether it's a store, bank, ATM, transportation facility, restaurant, or hospital—every facility must have entrance doors that bring in bright light compared to the interior space. WDR cameras can compensate for areas that are too bright or too dark and provide a sharp snapshot or video.

Garage

In a high-contrast scene where cars often enter a parking lot, a darkened garage, and a car with bright headlights heading towards the surveillance cameras, the WDR camera will be able to capture license plates more clearly.

Window Side

In spaces where sunlight pours through glass panes, casting sharp contrasts of light and shadow across interior spaces, WDR cameras meticulously balance the intense glare from the outdoors with the softer indoor lighting. By doing so, they ensure that every detail, from the expressions of people by the window to the movement of curtains in the sunlit breeze, is captured with precision.

Outdoor

The sun changes position throughout the day. Outdoor surveillance cameras often face strong sunlight, contrasting with the shadows of buildings or areas without sunlight, WDR cameras can compensate for this difference and offer a clear image.

To further enhance your security with high-quality video capture in challenging lighting conditions, FS offers various security cameras with WDR technology, such as the 5MP bullet PoE IP camera, the 2MP dome network camera, and more. Not only security cameras, FS also provides video surveillance solutions, including the solution for enterprises, the solution for retail supermarkets, and the solution for campuses. 

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