This is a photo of eerie light as the storm hovered over Bow Lake in Banff National Park. Shortly after I took this picture the storm unleashed its fury. I used a Nikon D 7100, Nikkor Zoom Lens (18-200 mm.), with a Hoya Circular Polarizer. I used a Gitzo Tripod and Arca-Swiss Head. The ISO was 100, F/16, 1/10th second exposure, and a Focal Length of 18 mm.