How to Achieve Those Soft and Silky EffectsWater in motion is ever-changing and ever-magical. That's especially true when it comes to slowing down the shutter speed and capturing a beautiful sense of soft movement as you see in boulder waterfalls and slides.
This fluid-motion technique can be applied to all types of waterfalls, streams, ocean surf, fountains, and even lawn sprinklers. How slow is "slow"? To blur flowing or falling water, start with a shutter speed of around 1/8th second, and then work your way down from there - into the 1/4- to 1/2-second range. The ultimate in silky smoothness, though, generally doesn't start to set in until about a full second or so. Longer exposure times increase the slow-motion effect.
But this "Going with the Flow" technique comes with a "rule": Photographing running water is not a precise science - so it always pays to experiment.
Experimenting With Fundamentals in Photographing Boulder Waterfalls and SlidesWater's speed
Slower-flowing water requires longer exposures to obtain the fluid-movement look, while fast or cascading water can be blurred with not-quite-so-slow shutter speeds.
Distance between camera and water: The more you magnify your subject in motion (i.e., by physically moving in closer or by zooming in tighter), the easier it is to blur it. More distant scenes require much slower speeds to convey that soft-movement look.
In any case, long exposures don't just happen. Most, or all, of the following must be in place in order to slow down your shutter speed:
Your lens's SMALLEST opening (HIGHEST f/stop number) will automatically result in the slowest possible shutter speed for the given ISO and lighting conditions. Side benefit: a wider depth of field (what's in sharp focus from front to back in an image). How to do it: In Aperture Priority, choose a high f/stop number. The camera's auto-metering system will then compensate for the small aperture by lengthening the exposure time.
Lastly ... More photos:
Article by Kerry Drager. To learn more about photography, explore the many online photography and Photoshop classes offered here at BetterPhoto.com.