This was quite the trip. Temperatures ranging from -20F to 5F. Truly a magical experience. My camera (Canon 20D) worked perfectly in these conditions although batteries were fully drained from the cold in just a few shots. Hand warmers were the key to keeping the spares warm. All shots were approximately 30 seconds (20-40) in duration (RAW) although I also varied the ISO (like the film speed) to get the exposures that I wanted.