(1) Externally illuminated signs shall be served by light fixtures that are shielded and directed downward. The average level of illumination on the sign face shall not exceed three (3) foot-candles and the ratio of average to minimum illumination shall not exceed two to one (2:1).

(2) Internally illuminated signs should be designed with light lettering or symbols on a darker background. If fluorescent lighting tubes are utilized, they shall be spaced on at least twelve (12) inch centers and be mounted at least three and one-half (3 1/2) inches from the sign face.