When taking photographs of waterfalls, I generally like to use long exposures. Longer exposures provide time for the water to flow enough to introduce some blur. The amount of blur will directly correspond to the length of the exposure. Some blur helps make the water appear softer and smoother.

The amount of blur is a matter of personal preference. And, the appropriate shutter speed will depend upon the focal length of the lens and how fast the water is moving. Things are so much easier with digital cameras as it is now just a matter of experimenting with a variety of shutter speeds and reviewing the images on the camera's LCD panel to determine which effects are preferable.

One challenge is achieving long enough shutter speeds. Sometimes, there is simply too much light to allow for shutter speeds of several seconds--even with the ISO set to the base level and with the narrowest of f/stops. The use of a neutral density and/or polarizing filter will reduce the amount of light entering the lens. Of course, it also helps to shoot waterfalls on a cloudy day as there is less light to begin with.

For this image, I used a Singh Ray Vari ND filter. The Vari ND allows the photographer to dial in the strength of the ND filter. To achieve a shutter speed of 8 seconds, I dialed the ND filter to near its maximum power (using about 7 stops of effect). I also went with a narrow aperture of f/13 and the base ISO of 100 for the Nikon D800.

This image of a man-made waterfall was captured at Lake Katherine in the Chicago suburb of Palos Heights:

Lake Katherine waterfalls