The ISO adjustment range of the USB camera module varies depending on the specific model and sensor type, and there is usually no unified standard. However, it can be summarized and analyzed through parameter ranges and functional characteristics:
Parameter range: The sensitivity adjustment range of some USB camera modules may be similar to the ISO Settings of traditional cameras, such as from 100 to 6400 or higher. However, not all USB cameras offer a clear ISO value adjustment option; instead, the ISO sensitivity is indirectly controlled through parameters such as exposure time and gain.
Functional characteristics:
Automatic sensitivity control: Many USB cameras support automatic exposure control (AEC) and automatic gain control (AGC), which can automatically adjust the sensitivity according to ambient light without the need for manual Settings.
Manual adjustment options: Some professional-grade USB cameras may offer the function of manually adjusting the ISO sensitivity, allowing users to adjust the ISO value according to their specific needs.
Sensor limitation: The adjustment range of the sensitivity is limited by the performance of the camera’s sensor. For instance, a global shutter image sensor may offer higher sensitivity adjustment capabilities in low-light conditions while reducing noise.
Adjustment range in practical applications:
In practical applications, the sensitivity adjustment range of USB cameras may be limited by software and drivers. For example, when adjusting through the OpenCV or v4l2-ctl tool, the available parameter range may vary depending on the camera model.
Some cameras may support a brightness adjustment range from -255 to 255, but this is not directly equivalent to sensitivity adjustment. Instead, it achieves a similar effect by adjusting the gain of the image signal.