I was out at sunrise at one of my favorite Sierra rock water locations and the water was moving very fast. My camera was set up on the tripod and favorite images were being created. The question I have been asked many times is what shutter speed to use on moving water and my answer is how do you want the water to look? The choices are tack sharp with water drops in the air stopped in motion, wavy unreal ribbons of smooth white velvet or something in between? In most of my images I usually prefer the long exposure smooth look. To achieve this look the exposures are between 5 seconds and 30 seconds depending on how fast the water is moving. I use one or two three stop neutral density filters to help the camera get to these exposures and sometimes I even add a polarizer to made the exposure even longer. To make your job easier shoot on cloudy days or before the sun rises or sets as the sun on the water makes it very difficult to get to those long exposures in addition can add contrast problems into your images. I have included a few images as examples.
Now go make some images!
Gary