shoot at f22 for 5 minutes, anther exposure @f22 for 10 minutes, another @22 for 20 minutes, another @ f22 for 40 minutes. Don't bother with a light meter Do bring a folding beach chair to sit in. Remember what the light is like and keep a journal. Night photography is trial and error. Also check out the site called The Nocturnes for best practices in night photography