The two 30-minute exposures above are from a Mare Island Naval Shipyard event hosted by The Nocturnes. Both images were made using existing light -- no moonlight or light painting were involved. An Olympus 18mm f/3.5 lens was used with an adapter on a Canon 5D Mark II for both photos. The camera was facing south in the image on the left, and north on the image on the right. Photographing the same structure from both sides was an interesting exercise. Which one do you prefer?