Sunset clouds streaking over time over the badlands of the Red Deer River valley at Horsethief Canyon, north of Drumheller, Alberta.Admittedly a rather surreal effect but submitted for fun A stack of 300 images stacked as with a star trail image but in this case with short exposures taken at sunset as the clouds lit uo and were moving out of the west toward the camera. So the stacking created the streaking or trailing effect. I smoothed some of the stairstep effect introduced by the interval