If the camera is close to obstacles, such as walls, shelves, door frames, or a lamp next to the camera lens, it will reflect the camera’s infrared light back to the camera, causing only nearby objects to be visible while the rest of the image will be very dark.
To solve this problem, try adjusting the camera’s angle and direction so that nearby surfaces or objects are not within its field of view, or move objects near the camera that might reflect infrared light; alternatively, you can turn off the infrared light in the application.