pretty good info for capturing the aurora:
How to photograph the aurora borealis | aurora borealis photography
"Shutter speed is everything. Faster is better. Yes, yes, I know, you can always get creative, try some slo-motion and long exposures and make some really neat photos. Great, but faster is still better. Try to keep your shutter speed under 30 seconds (maximum), if at all possible; I’ve had good luck with images in the 4-10 second range. I’ve shot with shutters speeds as low as 2 seconds, and high as one minute.Faster is better. You simply can’t beat shutter speed for aurora borealis, or northern lights photography.
So how do you achieve higher shutter speeds under a night sky? ISO is your friend. I’m comfortable with my D700 shooting at ISO 1600, but on my older, equally 12mp resolving D2x, I don’t like to go above ISO 200. That’s a 3 stop difference. If we look at how they plays out in this situation, let’s imagine my D2x is shooting at ISO 200, and the shutter speed yielded is 30 seconds. I have the D700, at ISO 1600 (you are shooting the northern lights with more than one camera setup, aren’t you? You should be; more on this later) yields an equivalent exposure at 4 seconds. That’s an awfully big difference
If we factor in the long exposure Noise Reduction recommended for this kind of time frame, that 30 second exposure turns into one minute between photos, and the 4 second exposure is 8 seconds, though I could also skip NR for a 4 second exposure. This means I could shoot 15 photos with the D700, to only one image with the D2x. That’s an incredibly vast difference in number of photos alone. It also gives me way more control over exposure, simply because I can shoot, adjust the exposure, or composition (more on this later) and shoot a corrected image, all while the D2x is still powering away on my first photo. Fleeting and active as the aurora can be, shoot as fast as you can.
The critical reason for a higher shutter speed though is this; the detail you will get in the resultant photos. A longer exposure tends to yield more of a ‘sheet’ of color, which can be cool, of course, but loses all the detail of a faster frame. 10 seconds and less is where you want to be, if possible. An additional reason is anything beyond 30 seconds, unless you’re shooting ultra, ultra wide, and the stars will begin to be recorded as miniature trails, instead of the fine sparkly dots you want them to be. As a general rule, 25 seconds or less, with a 24mm lens, is great. The longer the exposure, the wider the lens will need to be to keep the stars from trailing.
So, now you have your first step; jack up the ISO. Next, you want a fast lens; an f2.8 lens is typically considered (in nature photography) to be a fast lens. Most northern lights photographers I know of have at least one f1.4 lens. That’s 2 stops faster than a f2.8 lens, and again an immeasurable difference. Photographers LOVE to say how it’s the photographer, not the gear that matters. While I understand their point, they miss a greater point (for more on the subject - Your gear will critically impact your work). Faster is better. At the very least, get a 50mm f1.8 lens, a relatively cheap lens that’s very fast and sharp. It’s not quite as wide as you’ll want, but the shutter speed will be a boon.
Now you have a fast lens, you’ll really want a wide angle lens. This will be your primary northern lights workhorse lens. If you can’t afford an expensive fast wide angle zoom, like Nikon’s Herculean 14-24mm f2.8 lens, buy a 24mm f2.8 prime. It’s relatively cheap, reasonably fast, sharp, small and compact and easy to use. A great choice. A 24mm f1.4 lens is generally considered ideal.
By the way, I wouldn’t worry too much about sharpness here. Some folks worry about this, and particularly corner sharpness on the superfast wide angle lenses. Rarely is this going to be an issue, imo; you’re not shooting enough detail in the image to be overly concerned about this. Most any decent 2.8 lens or faster will be just dandy.
Note also that these lenses all become ‘less wide’ on many digital SLR cameras, the infamous DX bodies; If you shoot a ‘crop factor’ body, you’ll most likely want a wider lens. You’ll also want a faster lens, as most of those bodies don’t have the extreme high ISO quality of the full frame or FX bodies.
Active display of the northern lights over the Chugach Mountains, near the Matanuska Glacier, Alaska. Please click on the image above to view a larger view of this photo.
In brief, you want a fast wide angle lens, as well as possibly a midrange zoom; 28-70mm is a great range. You’ll want to be able to shoot at higher ISO’s, so whatever camera you can manage that provides a high quality high ISO option is the choice here.
Next, you need a tripod and good ballhead. You can’t handhold this stuff. And you can’t “make do” with resting the camera on a rock or backpack or whatever other workaround we squeeze out when in the field. Bring a sturdy tripod and ballhead.
Make sure they’re both cleaned and functioning at absolute optimum performance; cold weather does weird things to equipment, and if you’re fussing with the tripod at home, it’ll be impossible to manage in the cold night air. Any water in your tripod, if you’ve been shooting elsewhere, will freeze up and the tripod will be next to impossible to maange. Factor in how cold your hands will be, and you’ll be in tears of frustration, pain, cold and loneliness (no one else will wait around and hang out if they have to put up with this). So clean, dry and re-grease your tripod BEFORE you leave home.
Bring a cable release. I generally don’t shoot with mine when I’m photographing the aurora borealis, but that’s because (a) Nikon’s screw-in cable release mechanism completely sucks, and (b) with shutter speeds in the 4-30 second range, I don’t really need one. But, if I need or want to shoot a longer exposure, then a cable release is a must have. So have it handy. Be prepared though; that lovely pliable cable release you own will become one stiff, expensive and very brittle (in other words, breakable) cable in arctic temperatures. So be careful with it, and carry a spare if possible (keep it your vehicle).
Remove your filters; without going into all the technical details, the northern lights and filters don’t jive, so remove ANY filter from your lens. Northern lights photography is not done with a UV filter on your lens. Or any other filter.
Bring extra batteries and CF cards, and keep them in an inside pocket of your puffy down jacket. Remember, supreme cold eats batteries, even the magical hundred forty dollar Nikon batteries; I bring 2 extra. I’ve never had an issue with CF cards failing, but I know some folks who have, so I highly recommend the SanDisk “Extreme” series cards if you’re shooting in cold temperatures; at the very least, have a few of those along. (Note: it’s not likely to be that kind of crazy cold temperature if you’re shooting the Alaskan aurora borealis in September; even in October that would be unlikely. But tonight it’s mid November, and the temperatures across interior Alaska are in the -20 to -40 and colder range, so stand warned).
My final note on camera gear (and this one I’ve not seen anyone else mention in similar articles around the web). Shoot with 2 cameras, 2 tripods, 2 ballheads, etc; Aurora borealis photography is not about perfect mobility in the field, so it’s the perfect time to try your hand with a 2 camera setup. I’ll set up 2 tripods and cameras, and shoot with both. I can have an ultra wide lens on one body, say 14mm, and simultaneously shoot with a 24mm, or 28-70mm or 50mm on the 2nd body. It takes a little practice, but there’s simply no reason not to try this. We can’t ever predict what the next display or burst of the aurora might be, so we’re always guessing and shooting. More options are generally going to be helpful. So get out both your cameras, and practice shooting with both together. You can try some long exposures with that backup body you carry about with you, while your main body is firing away every 8 seconds........."