Cirrus clouds above side-by-side BART and Caltrain tracks, between Millbrae and San Bruno, California.

Shot with the Nikon D70s and the 18-70mm f/3.5-4.5 zoom at 46mm, ISO 400, f/9, shutter 1/1000 sec. Cropping, white balance, exposure, levels, highlights, and monochrome adjustments in Aperture.