Sky & Telescope - May 2024 - 33

enhance the color response in your images. These cameras
can pick up more of the reds than their non-modified counterparts
while still retaining a natural overall color balance.
Camera Settings
If you dabble in landscape astrophotography, then many of the
same approaches apply here. The big difference is attempting to
freeze the motion of these shimmering, ever-changing displays.
Start with an exposure of 15 seconds, with the ISO set to
1600 or, if you have a newer camera, ISO 3200 or even 6400. If
the display is bright and rapidly changing shape, you'll want to
lower both the ISO and shutter speed - this will increase the
dynamic range in your photos. Some aurora displays are bright
enough to capture in exposures of only a couple of seconds.
Another trick to try is stopping down the lens aperture,
especially while shooting with a bright Moon in the sky or
a bright aurora display. Stopping down from f/2.8 to f/4.5
or more both reduces lens imperfections such as coma and
increases the depth of field, resulting in a sharper foreground.
This also reduces the need to perform a technique known as
focus stacking. Focus stacking is a method in which you focus
on the sky in one image, refocus for the foreground, and then
combine the results in post-processing.
Be sure to monitor the histogram in your camera as the
display changes brightness. The key point here is to avoid
overexposing the brightest parts of the aurora by keeping the
peak of the histogram slope from being cut off at the right.
While you can slightly underexpose a scene and still get good
pictures, you can't recover overexposed areas.
Once you have seen and photographed a few aurorae displays
from home, you might start dreaming about excursions
to specific locations just to capture them. If you're planning to
travel far away for an aurora expedition, you'll want to utilize
apps such as Photopills or PlanIt Pro to help you gain insight
into the locations you have in mind. These apps let you visualize
the landscape and sky accurately to determine where to set
up, long before you arrive. And be sure to pick a few locations
that take advantage of the direction of magnetic midnight.
Finally, though aurora photography doesn't require much
post-processing, a little enhancement and color balance always
helps. Programs like Adobe Lightroom enable you to lighten
the shadow areas (like the foreground), control highlights,
and perform contrast and saturation adjustments quickly and
easily. For the more advanced crowd, Photoshop is king. It does
everything Lightroom can do and much, much more.
As we enter solar maximum, now is a wonderful time to
explore photographing the aurora. There should be plenty of
opportunities to catch these dramatic celestial lights over the
next several years. And who knows - we may experience a big
geomagnetic storm that pushes the auroral oval far enough
south that you can witness a display from your own backyard.
Bundle up, and good luck!
¢ MARYBETH KICZENSKI can often be found chasing the
northern lights in the Great Lakes region of the U.S.
REARVIEW Top: It's fun to get creative with your compositions. This
image uses a car mirror to include the aurora in the same frame as the
center of the Milky Way above the Mackinac Bridge in Michigan.
REDEYE OPPORTUNITY Bottom: Overnight flights are an unusual
opportunity to see a bright aurora display, though you may need to
get creative when blocking the interior lights of the plane. The author
grabbed this remarkable shot while flying over Canada with the same
Nikon Z6 and 20-mm lens used in the image on the facing page. Total
exposure was 1.2 seconds at ISO 6400 with the lens set to f/2.
sk yand tele scope .o r g * MAY 2024 33
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Sky & Telescope - May 2024

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