I find waterfalls to be one of the most interesting subjects to photograph. I often go back to a fall many times to reshoot the scene under differing light and waterflow conditions. It seems that the look changes every time I return. I have found that the effect that brings out the best look involves shootting at a slow sutter speed. This gives the water a silky smooth feel and hides some of the background rocks and ruggedness. Occassionaly I will shoot at very high speed to get a stop action view as a contrast to the silky look.