Bad quality at night on stick up cam

I have two wired stick up cams, both outdoors on opposite ends of the house. Both have excellent daytime video quality. At night, even though lighting conditions are the same, one has great clarity, the other is so cloudy the video is unusable. I've cleaned the front of the camera, but there is no change. Settings for both cameras is the same (color nighttime set on, but I've set it off to see if there is a difference, there isn't).