Aurora Borealis, looking north and just above the horizon more or less right at the constellation Cassiopeia from a position to the east of Glasgow, MT. You can also see two satellites tracking through the image, one northwards, one southwards, and a military jet zipping along westward near the bottom of the image, that one is easier to see full-screen. Busy night, eh? Each frame here represents about four seconds; the playback is quite a bit faster than that, so this qualifies as bona-fide time lapse. The clip was constructed from 40 still frames from my EOS50D, taken the evening of the onset of the April 3-4-5-6 geomagnetic storm, all from the same point and with the same camera settings (details below.)
***Let this load, then play it at least twice... flickr, aside from crushing the resolution, seems to have a problem with replay speed in some browsers. This should run for a total of about four seconds.
I uploaded this at about 4x this resolution, and was very disappointed to see it reduced down so far.
Oh well. I used Canon's 50mm ƒ/1.4 lens, wide open, after manually focusing it on a star. All these shots were taken at ISO 3200, 4 seconds exposure, from a fixed and locked tripod, adjusted and balanced to the same criteria using Aperture 3, then combined using the Mac's movie software and converted from .dv to .mp4 using Handbrake.