It was shot with a 1DMKII and it is three shots stitched together. I have blown up single shots up to 20x30 with no problem at all so I am confident this would enlarge quite well. The only issue with aurora shots is often the stars have a small bit of streak to them which is simply unavoidable. I have yet to print this shot. I have not used lambda printing before. If you have a good lambda print house to recommend I would like to hear any recommendations. It is quite stunning, isn't it? Thanks for the comment. I'll post a variation on this theme shortly (another pano of the same subject).
The exposure, I'm confident, was roughly 15 sec at f2.8, probably ISO 400-800. The camera holds up to cold temps very well. It was about -30F when I took this. The biggest problem is not breathing on the camera and keeping my hands warm. I have 6 batteries and have gone through all six in a long night of aurora shooting in those temps, which is saying something for those batteries which can last an average person a week. chuckle.