Doorways, Fort Point, San Francisco

I photographed this image on January 6, 2012. Fort Point is located under the San Francisco end of the Golden Gate Bridge. Work on building Fort Point began in 1853 and it was completed around 1861. It became a National Historic Site in 1970. I have photographed Fort Point a number of times, including this same image. However, with better knowledge and equipment I have  made this image better than any of the previous attempts. I used 2 Sigma DP1 digital cameras mounted next to each other on a panoramic device I constructed which allows the cameras to rotate up or down around what is called the entrance pupil of the lens. This enabled me to tilt the cameras slightly downward to make one part of the image, then slightly upward to make the other part of the image. I blended the two parts of the image together using  a computer program called Panorama Tools Graphic User Interface (PTGUI for short). The exposures were 5 seconds at f/8 (ISO 50).