I could not resist photographing this bison enjoying the soothing, relaxing heat of a small geyser basin in Yellowstone National Park. This is when a long telephoto is your best friend! A Nikon 500mm Phase Fresnel lens (a super sharp, lightweight lens that you can handhold all day) gave me the reach I needed, while not disrupting his spa time. I prefer not to disturb wildlife in their natural setting. I am after authentic photographs that depict a natural moment.