Seeing the Northern Lights is one of those things that is on the list of things to do in this lifetime. Mark Dubovoy provides some great background on what the Aurora Borealis is, best time of year to see, how to get there, and most importantly tips and techniques to successfully photograph the phenomenon.
I would highly recommend to all nature lovers that they try to experience the Aurora first hand. I would also recommend that one spend the time and effort to try and catch a really intense Aurora, as opposed to an average or below average one. Unfortunately, the probability of being in the right place, at the right time, with the right atmospheric conditions is low. It may take patience, perseverance and a number of trips before one is lucky enough to experience an intense Aurora, but the effort is definitely worth it. To experience an intense Aurora is nothing short of phenomenal. -Mark Dubovoy
See his article Photographing the Aurora Borealis. (via Night Photography Blog)
