The forecast said Kp5 for three consecutive nights, which in the Cairngorms in February means one thing in practice: pack for minus fifteen and be prepared for absolutely nothing to happen anyway.
Night one was cloud, wall to wall, from the car park to the summit. Night two cleared at 2am, forty minutes after the display had already peaked according to everyone else’s timelines online. Night three — the one nobody was watching for — the sky just opened up over Ben Macdui a little after 11pm and stayed that way for two hours.
The sequence from that second night is eleven thousand frames at eight-second intervals, camera strapped to a slider moving at roughly a millimetre a minute so the parallax on the corrie edge reads properly once it’s cut together. Battery life at that temperature is the real limiting factor, not card space — plan for half of what the spec sheet claims.