From the photographer: “The featured 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, 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.”

Technical details:
There are two sequences each with each of the following two time-lapse cameras:

– TTArtisan 11mm full-frame fish-eye lens wide open at f/2.8, on a Canon EOS R
– 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
Editing was in Final Cut Pro.



comments (7)

    Leave a comment