this is about 7 or so different shots of lightning. Shot all on the same night with the camera in the same position (I shot using a tripod and cable release set on continuous). Each exposure was about 8 seconds long. I shot for about five minutes until my memory card filled up--about 150 or so exposures and I got about 10-15 with at least some lightning. Thought it would be cool to combine them all--if i spent a lot more time I could make the transitions smoother. It was tough as each shot the sky looks so much different. Thats where the blending modes helped a bit--I used screen and pin light on a couple of the layers.