I recently spent a couple of weeks up in Arctic Norway shooting the Northern Lights. The principle cameras I used were the Sony A99, NEX5 and a PMW-F5. We had some great Aurora displays but also some incredibly challenging conditions including so much snow that we were almost snowed in and temperatures that got down to -34c. The average temperature when shooting the Aurora was -23c. Overall I was very please with the A99 although it could be a little temperamental below -20c. I had to keep it powered up and covered with a small insulating cover to prevent the shutter from freezing up. Almost every camera on this trip suffered from the cold at some stage. This video is made up of still frames compiled as time-lapse. Exposures ranged from 10 seconds to 2.5 seconds at 1600 and 3200 ISO.
Borealis. The Incredible Northern Lights, Aurora Borealis of February 2013. - YouTube

Very Nice.

Amazing work!