I have the fogging problem on cameras mounted in remote locations over grass (the ones mounted over concrete don’t have this problem). The same dew that forms on the grass also forms on the outside of the lens. I’ve tried an an anti-fog solution and it didn’t work. I tried Rain-X for plastic, and it just made the droplets a little larger. My next step will be to take a fish tank aerator pump which will be enclosed in an electrical box near the camera and run the plastic tubing to the camera. I will position the end of the tubing above the lens so air will blow down across the lens. The pump will be on a timer so it will only run at night. This should stop the dew from forming on the lens. I’ll report back after testing.