By Jorge Duenes

A U.S. border patrol vehicle is seen from the Mexican side of the border while driving near Otay Mountain on the outskirts of San Diego, California June 6, 2010. REUTERS/Jorge Duenes

Just outside Tijuana there’s a section of the USA-Mexico border wall that follows very irregular terrain and where, attracted by its curves and steep drops, I’ve taken many pictures. It was there that I decided to photograph the Border Patrol making its nighttime rounds along the winding road in the dark.

After two months of waiting for the right weather, I asked my father and brother to drive me to a place on the highway from where I could hike to the spot I had marked on my map.

A U.S. border patrol vehicle is seen from the Mexican side of the border while driving near Otay Mountain on the outskirts of San Diego, California June 6, 2010. REUTERS/Jorge Duenes

My backpack weighed heavily on me, as I carried two cameras, three lenses, a tripod, binoculars, a tent, jacket, food and drinks. With all of this gear, I walked quickly through the scrub in a region frequented by robbers and illegal migrants. It took me an hour and a half to reach my destination atop a hill some 400 meters high.

I started taking some photos before nightfall, but only around 9 p.m. was it dark enough to begin my mission — to take time lapse photos of the Border Patrol. To keep the shutter open, I used a piece of an aluminum can to jam the button down.

A U.S. border patrol vehicle is seen from the Mexican side of the border while driving near Otay Mountain on the outskirts of San Diego, California June 6, 2010. REUTERS/Jorge Duenes

I waited the whole night to make a total of 14 photographs of the patrols and their unpredictable movements. Around 3:30 am, a patrol crossed in front of my view from east to west, with enough fog to make the image even more interesting. The majority of the photos were taken with exposures of between five and seven minutes each on my Canon 40D set at ISO 500.