I. 120 dB Wide Dynamic Range: Why Is It Capable of Handling Scenes Where Both Bright and Dark Areas Coexist?
Key Reason: Wide Dynamic Range Imaging and Adaptive Exposure Technology
Wide Dynamic Range (WDR) refers to a camera's ability to capture details in both bright and dark areas within the same frame.
For example, during nighttime drone inspections, the following may appear simultaneously in the footage:
- Bright headlights, streetlights, or intense light emitted by electrical equipment;
- Roads, buildings, and the surrounding environment with low light levels;
- A person or object located at the boundary between light and shadow.
With standard cameras, two scenarios may occur: areas of intense light may appear washed out, or the camera may reduce exposure to capture the bright areas clearly, resulting in the loss of detail in the shadows. However, thanks to full-sensor adaptive exposure and anti-overexposure design, the camera can handle sudden bursts of intense light—such as headlights or lightning—and minimize the loss of detail caused by overexposure.
The technical principle behind it can be explained as follows:
1. The sensor collects light information: It converts light signals in the scene into electrical signals.
2. Control exposure: Adjust parameters such as exposure time based on the distribution of light and dark areas in the frame.
3. Wide Dynamic Range Processing: Preserves as much detail as possible in both bright and dark areas through the sensor’s inherent wide dynamic range capabilities or methods such as multi-exposure fusion.
4. Image Processing Optimization: Adjust the image's brightness, contrast, and other parameters to make details in both light and dark areas clearer.
120 dB is a performance metric for wide dynamic range, typically indicating the dynamic span between the maximum and minimum distinguishable optical signals that a device can process. This applies to dynamic range defined as the ratio of electrical signals.
II. Minimum Illumination: 0.003 Lux—Why Can It Still Capture Color Images in Extremely Dark Environments?
Key Reasons: High Sensitivity and Low-Noise Image Processing
Illuminance (Lux) is a physical quantity that measures the amount of visible light received per unit area.
The lower the illuminance, the fewer photons the camera typically receives, making the image more prone to problems such as insufficient brightness, increased noise, and color distortion.
To achieve full-color imaging at ultra-low light levels, the following technologies are typically required in combination:
1. High-sensitivity image sensors: High-sensitivity sensors are able to more effectively utilize the faint light entering the lens and convert it into an electrical signal that can be processed. Factors such as the sensor’s quantum efficiency, pixel structure, and readout noise all affect imaging performance in low-light conditions.
2. High light-gathering capability: Factors such as the lens’s aperture and light transmittance affect the amount of light reaching the sensor. The greater the lens’s light-gathering capability, the better it generally performs in low-light conditions, assuming all other factors remain constant.
3. Low-Noise Image Processing: In low-light conditions, the effective signal output by the sensor is weak, and noise may be more pronounced. Noise reduction algorithms can suppress some of the random noise and improve image clarity.
4. Color Image Processing: To preserve color information in low-light environments, it is necessary not only to have sufficient light sensitivity but also to properly process signals from the red, green, and blue color channels to prevent color distortion caused by insufficient signal strength.
From a technical standpoint, if a sensor can capture sufficient useful light signals under extremely low-light conditions and control noise through appropriate signal processing, it is possible to produce images with distinguishable colors in low-light environments.
Please note: 0.003 lux does not equate to complete darkness. If there is no visible light available at the scene—such as faint moonlight, starlight, or ordinary visible light—a standard visible-light sensor cannot capture accurate color scene information using low-light imaging technology alone.
