Take control of shutter speed
The right shutter speed is key to achieving the desired effect
1 Polarising filter
Polarising filters are perfect for shooting water, because they can be used to remove reflections from water if you wish, to deepen blue skies and to generally enhance sky detail. They can also reduce light entering the lens by up to 1.5 stops. Exposures of around 1/15 sec with a polariser fitted will practically freeze movement, but with a tiny hint of blur.
2 ND filter
Exposures between one and four seconds, depending on the speed of the tide, produce the most interesting results, since texture is still visible in the water and a greater sense of movement is captured. This four-second exposure was achievable thanks to the use of a three-stop ND filter and a polarising filter, which together reduced exposure by 3.5-4.5 stops.
3 10-stop ND filter
This shot was taken with a 10-stop ND filter attached to the lens to capture a long exposure. The result is completely smooth water and clouds streaking through the sky. In this situation, a exposure of longer than one minute doesn’t add much more blur to the water, but it does increase the blurring of the clouds, so it pays to experiment with the exposure time.