Nikon D5100, f20, 1/6, ISO 100, 18mm
There was a perfect Thunderstorm, one afternoon and I could see a lot of bolts in one section of the sky. I set up my camera so that it would take a shot every 5 seconds. This is the only one that had lightning out the 60 odd shots. I got lucky I guess.
See more photos of skies at SkyWatch