A friend posted this fantastic video from the Florida Institute of Technology testing out a new super high speed camera on lightning. You can really see the progression of step leaders downward from the cloud before the main lightning stroke surges up from the ground. You can view it at Slate.com at https://www.slate.com/articles/video/video/2016/05/lightning_storm_in_super_slow_motion_video_from_florida_researchers.html.
