In order to capture an "impression" of the eddies swirling like this, I dragged the exposure time to 20 seconds. To manage an exposure of this length, you need to drastically limit the amount of light that reaches your camera sensor. There are two ways to do this: One is to shoot when there's not much ambient light, and the other is to add a neutral density (dark) filter to the front of your lens. In this case, I did both. I was standing knee-deep in the stream by 6:20 AM, an hour before the sunrise, with a variable neutral density filter attached on my lens, and worked this location for over an hour. Curious to learn more? Sign up for lessons with me!