A Matter of Seconds
When shooting moving water, the most important decision is the choice of shutter speed (or exposure time). Most photographers prefer to use a long exposure time to convey a sense of movement of the water. However, how long is long enough? Half a second? Two seconds? Ten seconds? It is a matter of personal taste.
I took these photos at the Great Smoky Mountains National Park on a foggy spring morning. Generally speaking, when taking images of waterfalls and creeks, I almost always try to avoid direct sunshine hitting the water, since it will cause ugly blown out highlight areas. I much prefer to shoot during a cloudy day or when the scene is in the shade. A drizzling day works ever better!
One of the most useful accessories when shooting water is a polarizer filter. The filter serves two purposes: (1) it eliminates the glare from wet rocks and foliage, and, (2) it acts as a 1.3-1.7 stop neutral density filter to slow the shutter speed by reducing the amount of light entering the lens.
For the first photo, I used a Cokin Z-164 CPL on a Cokin-Z Pro holder mounted in front of my Canon 16-35mm F2.8L lens. I set the ISO to 100 and my aperture to F13. The CPL effectively reduces the shutter speed to 0.5 second, which is perfect to capture the sense of movement of the water in the creek. I also used a Lee 2-stop soft GND to prevent the sky from over-exposure.
Enchanted Creek, Great Smoky Mountains National Park
Canon 5D Mark II, Canon 16-35mm F2.8L @ 16mm, ISO 100, 0.5 second, F13, Cokin Z-164 CPL, Lee 4×6 2-stop soft GND.
On my second try, I added a Lee 4-stop ND (Neutral Density) filter in front of the above setup, resulting in a much longer exposure time (8 seconds). The slower shutter speed completely blurred the water flow, creating a dream-like mood that matches well with the surrounding fog.
Canon 5D Mark II, Canon 16-35mm F2.8L @ 16mm, ISO 100, 8 seconds, F13, Cokin Z-164 CPL, Lee 4×6 2-stop soft GND, Lee 4×4 4-stop ND.
The different shutter speeds created very different feels. Which version is “better”? It is in the eyes of beholders and I have heard different opinions from my fellow photographer friends. The first version is more dynamic and the texture of the foreground is lovely. The longer-exposure one is soft and moody. When you are in the field shooting, choose a shutter speed that works best for your personal style. If you cannot make up your mind, just try different speeds!