Wide dynamic range (WDR) technology balances the light on an image via image sensors (CCD & COMS) and digital signal processor (DSP). When part of an image is extremely dark but another part is so bright you can’t see any details, that’s dynamic range—the difference in lighting. Cameras with wide dynamic range (WDR) have special software that allows them to balance that lighting for one clear image. This makes them ideal for recording areas like store entrances where the contrast between the sunshine outside and the dim lighting inside can be extremely difficult to record.

True WDR – Provides crystal pictures in strongest lighting contrast conditions

Cameras have problems with underexposed and overexposed images because they can only accurately record the middle area of light between very dark and very bright. Cameras with WDR technology have advanced sensors that can produce a wider range of lighting, allowing them to record in a higher light depth.
Along with recording a larger range of lighting more accurately, WDR-enhanced cameras have two other ways of balancing light for better images. Tone mapping lets the camera or software automatically brighten dark areas and darken light areas.
Alternatively, the camera will capture several shots of the scene at different exposure levels. This creates overexposed and underexposed identical images, which the camera will combine. It takes the most balanced parts of both images, creating the recorded image you see. This method requires an extremely fast and light-sensitive sensor, however, and is only available on advanced professional cameras.

Backlight compensation (BLC) works by increasing the level of exposure for the entire image via digital signal processors (DSP), which divides an image or scene into different sections and adjust the lighting accordingly. Simply put, BLC works to brighten the whole scene on a video/image frame instead of balancing lights on overexposed and underexposed areas like WDR does, which in some cases, wash out some already overly-lit areas in an image/video.

BLC – Compensates light to the object in the front for crystal images. BLC technology has been used in CCTV/IP security camera with CCD image sensor to increase exposure for a whole scene, which performs better in a poorly-lit area or monitors areas without enough illumination such as the backyard, alley.

Highlight compensation (HLC) is a technology used in CCTV/IP security cameras to deal with image overexposed with lights like headlights or spotlights. Security cameras' image sensors detect strong lights in video and reduce exposure on these spots to enhance the overall quality.

HLC – Avoids the overexposure and blinding of videos day & night.