On a recent hike in the Cascade Mountains, Nancy crosses a footbridge and decides to photograph a river swollen with snowmelt. How does a photographer tame that frightening aquatic energy and transform the photo into one of graceful movement more appropriate for the healthcare environment?
The Wenatchee River, swollen with snowmelt, cascades down a steep mountain gradient and presents a dangerous aspect in this cell phone photo. Photo: © Donald J. Rommes
A sturdy metal bridge that once carried a train across the Wenatchee River now provides hikers with a way to cross the rapids. It is hard to not be impressed by the sound and apparent fury of the raging water as it surges towards and beneath the bridge.
Nancy stopped on the bridge and made a few exposures of the scene, but the harsh light on the foam of the waves only accentuated the frightening force of the cascades. After several unsuccessful attempts at a "normal" exposure, Nancy decided to use a slow shutter speed to smooth the water's movement.
Slow shutter speed smooths movement
But how to get a slow (1 second or more) exposure when it is so sunny?
Nancy dropped the ISO (the camera's sensitivity) as low as possible (64) and chose the smallest lens aperture (f22) but the required shutter speed was still too quick and had the result of "freezing" the water movement. The exposure needed to be much slower.
Nancy first tried a polarizing filter—which decreased the amount of light reaching the sensor (allowing for a slower shutter speed) while also decreasing the reflected glare off the water. The shutter speed was still too fast.
The utility of a neutral density filter
Finally, she went for a neutral density filter that cut the amount of light dramatically and permitted a shutter speed of about one second. The slow shutter speed allows enough time for an object in the scene (like bright foam on a cascade) to travel a long distance and trace a bright line on the photograph. The resulting long streak from the bright water creates a sense of time and movement—but movement that is more graceful and less forceful.
A slow shutter speed (1 sec) smoothed out the forceful rapids and created a more graceful, gentle movement that seemed more appropriate for the Iris Arts audience. Photo: © Nancy Rommes
A short video of Nancy on the hiking bridge. The video gives a better sense of the force of the river Nancy was trying to tame for the still photo.
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