Hi Dan,
I went last December for the Northern Lights in Tromso, Norway. Few lessons from my experience that i would like to share with you:
- Northern lights are best when the sky is clear (not cloudy, not snowing). that is why some of the guides generally chase the good weather first, then chase the lights. I had to also check the weather forecast daily when i was in Norway to decide when i go out to find the northern lights (to find a day where the sky during the time i'm out is likely to be clear)
- Do check the forecast of the aurora activity level, higher activity levels give you higher chances. (
http://www.gi.alaska.edu/AuroraForecast)
- You have to be away from the city where the light pollution spoils the visibility of the northern lights, so you either have to stay somewhere more remote, plan to drive out on your own, or engage a guide (not cheap). My guides drove us hundreds of kms to the Finnish border.
- do plan more days for viewing the northern lights, my first few days (even out with a guide were practically wasted as it was snowing and cloudy), luckily the week ended with fruitful results.
- as you will be pretty far north, it will be quite cold. guides will offer additional thermal suits that are very useful for staying out in the snow for long to wait for the lights. If you are on your own, do consider bring more layers or renting.
- for photography, you need a tripod, camera with long exposure capability and preferably remote trigger.
- for lenses, as wide an angle would be better, and preferably big apertures around 2.8 etc.
- If you want to take a photo of yourself with the lights, bring a flash too, and trigger it to fire at the end of the long exposure, you have to stay still for the 20-30 secs during the long exposure tho. you also need to use manual focus such that the subjects (humans) are in focus. might be good to practice before the trip.
- it might be a pretty long wait for the northern lights, so it'll be cold, dark and boring (for kids or older people who do not appreciate torturing themselves to wait for the spectacle). My nights out chasing the northern lights were generally from 8pm till 3am. do prepare for this.
i figured you would have read or found out about most of these already, but it doesn't hurt to repeat them in case.
If you are interested in finding out more about the Norway route, let me know and i'd be glad to share what i can. Good luck and have fun, it is really a great experience!