There were projections that the Northern Lights might reach as far as southern Montana, so I set up despite the clouds. The images were overexposed, in part due to the full moon and in part due to the f/2.8 setting. Upon further review, I shot at f/5.6 last year. The only thing I really learned from this star trails stack is that the clouds move fast enough to show visible gaps, even though exposures are only one second aprat.
