[Problem phenomenon]
After the infrared is turned on at night, there are many floating snowflakes in the picture, as shown in the figure below.

【problem causes】
It is mainly caused by the presence of more dust in the environment, and the direct reflection of infrared light on the nearby dust.

Generally, the phenomenon of rainy days is not obvious, and the dry weather is more obvious on sunny days.

【Solution】
It is a normal reflection phenomenon, the optimization method is as follows.

1. Turn on the anti-infrared overexposure (reduce the brightness of the infrared lamp), which can be improved to a certain extent.

2. The use of a large focal length lens camera can be effectively avoided.