Illumination. Brightness of electronic message signs shall be no greater than 7,000 nits during daylight hours and no greater than 500 nits during nighttime hours. However, regardless of luminance, no electronic message signs shall be illuminated in such a manner that creates glare conditions on adjacent properties or adjacent streets, impairs the vision of a motor vehicle driver, interferes with a motor vehicle drive's operation of a vehicle, or interferes with the effectiveness of an official traffic sign, device, or signal. All electronic message signs shall be equipped with a dimmer control and a photo cell, which constantly keeps track of ambient light conditions and adjusts the sign brightness accordingly. A written certification is required from the sign manufacturer, stating that the light intensity has been preset not to exceed the illumination levels established by this Subsection F, and that the preset intensity level is protected from end-user manipulation by password-protected software.