Capture the "Water Flow" Effect

One of the more pleasing uses of shutter speed in landscape photography is recording the flowing motion of water in rivers, steams and even ocean waves. The combination of motion and stillness within the frame is quite intriguing: it "idealizes" the water flow as it opens up the imagination to the complex physics of the world.

There is no set shutter speed that will accomplish this effect for every shot, as the rate of flow will differ in each scene. A good starting point might be 1/15 second. The angle at which you photograph the motion will have a profound effect on the result. Shooting at a right angle (perpendicular to the subject) will enhance the motion; shooting at less than a right angle will require a slower shutter speed to get a similar effect.

copyright George Schaub

To get this flowing water effect I set the camera on a tripod and set the exposure mode at shutter priority at 1/8 second, a guesstimate exposure. I bracketed one stop either way for insurance and got three exposures: the set exposure (1/8 second), 1/4 second and 1/15 second. My guess was right: final exposure: f/22 at 1/8 second. Note that I focused on the foreground rock to insure sharpness throughout the frame (28mm lens).

 The main issue you might run into when going for this effect is too bright a light level. In other words, even if you stop the aperture down to its minimum, working at the desired slow shutter speed may cause overexposure. 

To get around this:

1)    Set the ISO to the lowest number.

2)   Because of the brightness level you might “run out” of aperture to control exposure. In bright light, even at f/16 or f/22, you might only get a reading of, say 1/60 second, which is too fast to attain this effect.

3)   If that occurs you can:

a)   Find a spot where the light level is lower (shoot in the shade) or

b)   Place a light reducing filter over the lens, such as an ND filter (which can help lower light levels by two stops or more, depending on the ND filter strength) or polarizing filter (about 1.5 stops less light.) 

4)   Mount the camera on a tripod or other steadying device. (Of course, if shooting near the edge of the water or even in it make sure the device is rock solid before letting go. I speak from experience.)

5)   Use a cable release or remote shutter release accessory. Lacking same use the short self-timer shutter release mechanism. This helps steady pictures.

6)   Start at 1/15 second and go progressively slower in shutter speed. Use bracketing: set the camera in TV (or S on some cameras: shutter priority mode) and it will bracket with shutter speed settings.

7)   If you are close to the effect you want but are slightly overexposed, shooting in RAW format will give you a 1 to 1.5 stop allowance that you can correct later in processing. Any more overexposure beyond that will usually not be recoverable.