Using along lens to get close to the scene is something I have done in the past, especially when standing on the edge of a river and you can't get much closer. On this day I spotted the water rushing over a rock and set-up my tripod so I could capture a longer exposure. Zooming into the scene and using a exposure which is longer then what you can handhold I was able to capture the motion of the water as it made its way over the rock and further down the river.
