My 2-minute video presents time-lapses of the great May 10, 2024 display of Northern Lights, widely seen around the world during a G5-level geomagnetic storm when the planetary Kp Index soared to level 8, a rare occurrence.
I shot from my rural backyard in southern Alberta, Canada, at a latitude of 51° N. At my latitude we were north of the main arc of green aurora, though our sky still filled with curtains and rays converging at the zenith. They often appeared pink or blue.
However, as the movies show, the display got really bright only briefly at times, sometimes for just a minute, compressed here to seconds.
Colours were sometimes visible to the eye, notably pinks. But as always, the long exposures (3 to 8 seconds each for most of the time-lapse frames) bring out the colours of auroras (especially the reds and blues) that are there but are too faint to excite the colour receptors, the “cones,” in the eye’s retina. So yes, the colours are real! Just because you can’t see them doesn’t mean they aren’t there.
Green and deep red are from oxygen. Blue is likely from nitrogen, and from interactions with sunlight illuminating the curtains in the upper atmosphere. Other colours, such as the brilliant pink that was a hallmark of this show, result from red, green and blue “primary” colours blending.
The short real-time video clip at the end shows the rapid pulsating or flickering effect at the zenith characteristic of a post-substorm “recovery period.”
Note the overall change in the direction of the “flow” of the aurora, from swirling around the zenith to a southward motion from top to bottom of the frame in the final clip.
Music is the selection Brought to Rome, by Francis Wells, a pseudonym for Swedish composer Johannes Bornlöf, and licensed through Epidemic Sound. Editing was in Final Cut Pro.
TECHNICAL:
I shot the time-lapses (two sequences each with each of the two time-lapse cameras) using:
- a TTArtisan 11mm full-frame fish-eye lens wide open at f/2.8, on a Canon EOS R, and
- a TTArtisan 7.5mm circular fish-eye lens wide open at f/2, on a Canon EOS R5.
Intervals were 1 second between frames.
The still images shown, including the circular 360° panorama at the end credit, were with the Canon Ra and Laowa/Venus Optics 15mm lens at f/2.
The short clip of real-time 4K video at the end was with the Canon R6 and TTArtisan 21mm lens wide open at f/1.5. I processed that video clip in Photoshop and the Camera Raw filter, using Photoshop’s video editing function. Unfortunately, I missed shooting 4K video when the overhead corona got really bright and fast moving, as that outburst was so short-lived I didn’t get a chance to get to the R6 video camera.
The manual-focus TTArtisan lenses are made for the Canon RF lens mount - I use them almost exclusively just for auroras. Ditto on the Laowa 15mm.
I processed the time-lapse frames in Camera Raw and Adobe Bridge, using LRTimelapse to vary the settings over the sequences. And that took quite a bit of fussing with, requiring multiple key frames (up a dozen or more) to accommodate the huge change in brightness in the aurora as sub-storms hit and subsides, and the occasional change in camera settings I applied during the shooting.
However, I used the program TimeLapseDeFlicker to assemble the intermediate JPGs exported out of LRTimelapse. I chose TLDF, rather than LRT for assembly, to use TLDF’s frame blending function, and its option to render at a slower frame rate of 10 frames per second, better for auroras than the usual 24 or 30 fps.
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