The surveillance camera was caught in the rain. Why is there fog?

Water enters the camera. When the rain is light, the heat generated when the camera works normally will accelerate the evaporation of liquid water and make the water inside the camera close to saturation. However, due to the low temperature of the window, water droplets will condense on the window glass, resulting in fogging of the image.

Therefore, when installing the camera, you must choose a better location, as shown in the figure below, which will greatly avoid the surveillance camera from being rained and prolong the service life of the camera.