Moving water is rendered as smooth and silky in many photographs. Photographers often use long exposures to allow the motion to blur the water within the image. Although this is usually my preferred method of photographing moving water, I sometimes like vary the shutter speeds to create different effects.

I selected a slow shutter speed (0.8 seconds) to smooth the moving water of Niagara Falls. To accomplish this slow shutter speed, I selected a low ISO (100) and a narrow aperture (f/11). As the sun rose, narrower apertures were required to retain the slow shutter speed due to the increased light. At some point, even the narrowest aperture won't allow for such a slow shutter speed. Then, the photographer is forced to use a faster shutter speed or to use a neutral density filter to reduce the amount of light reaching the sensor.

Horseshoe Falls

In this next photograph of the Lower Yellowstone Falls, I wanted a faster shutter speed to partially freeze the movement of the water. The faster shutter speed portrays more power from the Falls. I selected a shutter speed of 1/125th of a second. By using a neutral density filter, I kept the aperture at a sharp f/8 at the base ISO setting of 100.

Lower Falls rainbow In this picture of the St. Mary Falls at Glacier National Park, I selected a shutter speed that would render movement in the falls but also show some detail in the pools below the falls. In this case, a shutter speed of 1/6th of a second did the trick:

St. Mary Falls In this next image of a man-made waterfall at the Worth Water Reclamation District in the Chicago suburbs, a shutter speed of 1/30th kept some detail in the rapidly falling water and even more detail in the slower moving water below:

Falling water In this last photo of waves crashing up on Baker Beach in San Francisco, the last thing that I wanted to do was to smooth the water. So, I selected a faster shutter speed of 1/200th of a second.

Golden Gate Bridge

Selecting your preferred shutter speed is a matter of experimentation and personal preference. Slow moving water requires slower shutter speeds to render motion blur than rapidly moving water. Moving water that is further away in the frame requires slower shutter speeds to portray motion blur than water that is very close to the lens.

In the digital age, it is much easier to create what you are intending. I shoot the same scene at a variety of shutter speeds. The images can be viewed instantly on the camera's LCD screen. Or, you can view the images later and select the ones that work the best.