Shooting the Northern Lights?

[phild2k]

Do these look like logical exposure settings for shooting the Northern Lights with a Nikkor 20mm F1.8 wide angle lens on a Nikon D810:

F1.8 / 15 sec Shutter Speed / ISO 400
F1.8 / 8 sec Shutter Speed / ISO 800
F1.8 / 6 sec Shutter Speed / ISO 1600
F1.8 / 4 sec Shutter Speed / ISO 2000

Obviously there are no hard and fast rules and that it is very situational, but I'm looking for some rough guidelines.

Thanks.

 

[goooner]

I would try and check the exif data on some of the good shots on flickr, there must be thousands of northern light shots on there...

 

[phild2k]

Do they have an exif data search filter at Flickr?

 

[goooner]

Flickr Search: northern lights

I just typed northern lights in the search field. Just click on the photos you like, many of them do have exif data.

 

[TCampbell]

I'd use the Flickr search to find suggested exposures.

Keep in mind that since Earth is spinning, stars will grow "tails" on long exposures but how long depends on sensor size and focal length. For a full-frame camera, use the base of 600 and divide that by the focal length of your lens to get the number of seconds you can go without getting "tails". e.g. for a 20mm lens it's: 600 ÷ 20 = 30 seconds.

Light pollution is not your friend when doing this sort of thing so you want to get away from city lights.

Getting precise focus to infinity (so you don't have fuzzy stars) is a bit tricky because the stars aren't bright enough for the focus system on the camera and there's nothing for it to automatically lock onto. You can manually dial in the focus but at f/1.8 a very minor error will show up as a mushy photo. You might want to flip to live-view mode, turn off auto-focus, maximize the exposure (crank the ISO, etc.) and then do a digital max zoom on your lcd to get the stars focused... (then switch back to the settings you want to get the shot.)

 

[phild2k]

Thanks TCampbell - all good sound advice.

On focusing, I usually pre-focus on a very distant object like a mountain and then disable AF prior to the Aurora shoot.

Any comments on those approximate settings I listed?

 

[jsecordphoto]

When I have shot them, I start at iso1600-2500, f2.8, 15 seconds at 16mm. New england auroral events are typically nowhere near as intense as say, Norway, so maybe you'd use slightly different settings there. But I try and keep the exposures between 10-15 seconds, otherwise the spiking of the aurora blends together.

 

[Psytrox]

There isn't a "premade" setting for shoting northern lights. Although I don't have a lot of experience shooting northern lights, I'll share with you what I got.

The northern lights is, like the sun, and the moon, a light source. So, F1.8 is way over the top. I think between f8-f16, or maybe even a higher f-stop The northern light actually moves. So, with the 500/600/700 rule taken into account to your crop factor and focal length. You're looking at around 10-25 seconds exposures. Anything more than 30 seconds, will just make everything look mushy. Then adjust the ISO accordingly.

Work the way jsecordphoto suggested. Crank up the ISO, this way you can take the pictures quickly, and get the composition that you want. Then work your way down, tightning the F-stop, and reducing the ISO. Remember to think about the background and foreground as well, don't just focus completely on the aura. So many northern lights photo's out there which are boring because the photograph didnt think about composition.

You will have some time to take the photograph. Northern lights can last anywhere from a few minutes to hours. Keep in mind, it doesn't make a sound, and it's very unpredictable.

 

[jsecordphoto]

^ that is not the best advice. The aurora is not a light source at all, but a reaction in our atmosphere. It's caused by the sun, but comparing it to the sun as far as being a light source...no.

Remember this will be happening at night (duh), shooting at f16 or more? You'll completely underexpose your photo. Like a black screen underexpose. To even get a scene with a recognizable foreground at f16, expect an exposure of around half an hour at least. When photographing the Milky Way, to get a foreground exposure where my histogram isn't clipping the shadows, I'll shoot iso1600, f2.8, 8 minutes.

Trust me, shoot wide open or close to it, I wouldn't go beyond f4.

 

[runnah]

I took the approach I do for normal stars shooting and backed off slightly for the minimal extra light. Any exposure over 20-30 seconds runs the risk of start movement. Find out where you want to make the compromises. I don't like shooting wide open, but I will if it means lower ISO.

f/4 | ISO 1600 | 30 seconds | 17mm

K52A6960 by runnah555, on Flickr

 

[Psytrox]

^ that is not the best advice. The aurora is not a light source at all, but a reaction in our atmosphere. It's caused by the sun, but comparing it to the sun as far as being a light source...no.

Remember this will be happening at night (duh), shooting at f16 or more? You'll completely underexpose your photo. Like a black screen underexpose. To even get a scene with a recognizable foreground at f16, expect an exposure of around half an hour at least. When photographing the Milky Way, to get a foreground exposure where my histogram isn't clipping the shadows, I'll shoot iso1600, f2.8, 8 minutes.

Trust me, shoot wide open or close to it, I wouldn't go beyond f4.

The aura isnt a light source like the sun/moon, I agree. However, it is photons (cause by magnetic storms, from the sun, or something like that) being dragged to the north pole, which is what creates the aura, which does emit some light.

I looked at some of my older pictures, and they were taken at f4-5,6 at ISO 100. From around 15-30 seconds. However, I did wish I shot it at a higher ISO, for shorter speed (because of star trails), and higher f-stop because the background is slightly OOF.

(F4, ISO100, 30s)

Perhaps it was different for me in regards to background because I had some light from streetlights.

 

[goooner]

These are nice psytrox, but you shot them at f4, and suggested f8-16. What lens did you use here?

 

[Psytrox]

Thank you, I think I posted this on the forum earlier. This is taken with the 18-105 kit lens, Nikkor. Taken at 18mm
Obviously, this would have meant increasing the ISO to compensate. But my camera can easily handle the increased ISO noise.
F18 would probably have been too ambitious. But if I was there again, I would definitely try.

But the intention here isn't really to hijack OP's post. But I'm sure (hopefully) he will still get something useful out of this anyway

I guess, this all boils down to that it can be very situational and you won't know until you get there and the Northern Lights actually show up.

 

[TCampbell]

It is a light source... not entirely unlike the function of a florescent light bulb... just not nearly as bright.

Highly charged particles from the Sun hit the atmosphere. Typically this is triggered when a coronal mass ejection or CME from the Sun collides with the Earth ... really Earth's Van Allen radiation belt which magnetically deflects the particles from hitting us directly and funnels them around to our magnetic poles.

At the poles, the charged particles energize gasses in the upper atmosphere (mostly oxygen and nitrogen ... though oxygen is more common and this is the source of the 'green' light you typically see.) When an electron drops from a higher orbit to a lower orbit, the atom emits a photon and the wavelength of that photon will be dictated by the drop in the orbit of the electron. Two atoms of the same type aren't just similar... they're identical. The drop is always precisely the same... not just close. Consequently the color of the glow for the particular type of gas that happens to be glowing will also be identical.

You can find a bit more about it here: Auroral Colors and Spectra - Windows to the Universe

Most of the time we tend to see the green auroras. But there's also the violet/reds as well. In Runnah's photo you can see the violets and reds from higher altitude nitrogen glowing... but the green light (oxygen) is much brighter at a lower altitude.