What is Wide Dynamic (WDR)? Why must the backlight scene be turned on?

Question Scenario

When the camera is facing the glass curtain wall, the gate, or the garage entrance, the background is extremely bright and the foreground characters are very dark. Ordinary cameras can only choose one of two options: either the background is normal and the characters are black; or the characters are clear and the background is white.This is the typical strong backlight.

Principle of wide dynamics

Wide Dynamic Range by exposing the same scene twice for different lengths of time (one short exposure preserves bright details, one long exposure preserves dark details), and then composited by the image processor to render both highlights and shadows.The dynamic range after synthesis is expressed in dB:

• Digital Wide Dynamic (DWDR): Algorithmic simulation, about 60-80dB, with limited effect.
• Wide Dynamic Reality (WDR): Hardware double exposure, about 100 ~ 120dB, the effect is obvious.
• Ultra wide dynamic: some high-end models can reach more than 140dB.

Typical scenarios that must be opened

< table border = "1" cellpadding = "8" cellspacing = "0" style = "border-collapse: collapse; width: 100%" > ScenarioReasonSuggestion Bank/Store CounterOutdoor natural light intensity, indoor darkness≥ 120dB true wide dynamic Garage entranceThe difference between internal and external light is very large, and the license plate is easily exposed.Wide Dynamic + License Plate Exclusive Mode Glass façade lobbyThe background brightness is much higher than the faceWide Dynamic + Reasonable Fill <tr >Window/DoorLarge indoor/outdoor light ratioWide Dynamic + Adjust Mounting Angle

Debugging Points

• Wide motion slightly reduces the frame rate and clarity of the dynamic picture, and non-retrograde light scenes can be turned off for better image quality.
• When turned on, readjust the metering area so that the focus target (face/license plate) is in the metering center.
• When using with a fill light, take care to avoid new overexposures caused by the fill light.
• Not with Backlight Compensation (BLC)On at the same time, the two algorithms have different goals, and enabling them at the same time may be counterproductive.