Authors Note: This is an excerpt and update from a post I prepared for Singh-Ray Filters. This update includes new images to illustrate some of the techniques I employ to capture moving water.
Moving water – waterfalls, rivers, streams and surf – often presents unique challenges to the landscape photographer. The most common way to capture images of moving water is to use a slower shutter speed. But how slow should the shutter speed be? The answer largely depends on the effect you are looking for in the final image.
I normally divide my approach to shooting moving water into these three desired effects: Silky, Milky and Textural. The silky effect is generally a soft blur that contains some texture or threads of water. The milky effect shows no texture and the water is completely blurred. The textural effect is a mixture of the previous two. It conveys a sense of motion but contains more textural threads in the water. I could include stop motion as well, but it is not a water effect that I personally like. In many cases the "effects" are combined. The image above, is both silky and milky, as the shot captured the long finger-like water of the waterfall and the softness of other parts of the flow.
There is always a debate among some photographers that the motion look, in its various forms, does not look natural – that the stop-motion look is more “realistic.” It is a silly argument at best that has no right or wrong answer. Moving water consists of millions of molecules in motion. The human eye never actually sees that, any more than we actually see the molecules frozen in mid-flow. For my own work I prefer the motion look, the sense of softness it creates and the contrasts in texture that come from blending the flow of water with solid structure such as rocks, boulders, trees, and the shoreline. But it ultimately comes down to your preference as a photographer and your own personal vision.
But the question still remains. How slow or fast should the shutter speed be to effectively capture moving water? The answer largely depends on the water’s speed or rate of flow. Other factors such as the environmental conditions, time of day, and quality of light also come into play. The following shutter times are typical for my moving water exposures, but are by no means set in stone:
Silky effect for waterfalls and other cascades – 1/2 second to 2 seconds (Image 1, below)
Milky effect for waterfalls and flat moving water – 2 seconds to 30 seconds (and even longer) (Image 2, below)
Textural effect for waterfalls and flat moving water – 1/15 of a second to 1/2 of a second (Image 3, below)
So why are these times not set in stone? Because environmental conditions, time of day, quality of light, combined with technical factors such as camera position, ISO settings, aperture, and filters all have an effect on the exposure time. I do a lot of my water work in the early morning or early evening hours. The reason is that the light at these times of the day is lower in contrast. It is softer light that is devoid of the harsh specular highlights of mid-day. But foggy conditions and overcast skies are also great times to shoot water. These conditions generally extend the shooting times during the day past the golden hours. At these time frames, with lower ISO settings and apertures of f8 to f11, shutter times can start off beyond one second and approach 4 to 8 seconds. This is especially true in forested locations. And this is often before a filter has been applied.
I will stop here briefly and say that in nearly all shooting conditions and times, I use, at the very least, a circular polarizer. This essential filter reduces specular highlights on water surfaces and wet surfaces on rocks and plants. Additionally, a circular polarizer can allow you to reveal structure under the water. A polarizer can lesson the amount of light striking the sensor between 1.3 (Singh-Ray polarizers) to 2 stops (most other polarizers). So if my starting exposure is one second, the addition of a polarizer can extend the shutter time to 2-4 seconds. A solid or variable neutral density filter will further lengthen shutter time. For example, if you use a 3-stop ND and a polarizer, that 1 second exposure extends to 30 seconds. Because I use set apertures from f8 to f11, to achieve an extended depth of field, my approach to the capture effect depends on how and when I stack my filters, and whether I need to alter the base ISO of the camera. Remember from the exposure triangle that any adjustment of ISO or aperture will affect shutter speed. Since my apertures are generally set I make my shutter speed adjustments by altering the ISO and filtering.
It may seem complicated but consider the following scenario. I have arrived in the early morning at a waterfall with a high flow rate. Through several test shots, at ISO 50 and with a polarizer, I have determined that any capture beyond 1/2 to 1 second will create a shot with the water rendered as a formless mass, (Image 1 below). What I need is a little texture to bring out more details in the water. With a simple adjustment of the ISO to 400 I can shoot that waterfall at 1/8 of a second and add some much needed texture to the form of the water (Image 2, below). These two images were combined in Photoshop to render the final master file.
This all comes down to some very simple decisions in the field. What are my conditions? What is the speed of the water? Is it moving fast, moderately or slow? What is my camera position relative to the flow? Shooting straight on will give you a different effect versus shooting from the side or at an angle to the flow of the water. Ultimately the question I ask is what do I want to achieve in the composition? What kind of mood do I want to suggest. A milky or silky flow can convey a sense of softness whereas adding textural effects can achieve a sense of motion and power. From that starting point, I set up the composition, and make a series of test shots and study the effect on the camera’s view screen. Is the shot going to look good with the milky effect or do I need some texture? What combination of manipulation of the exposure triangle will produce the desired effect. When you consider the images below, think about how the rendering of the water contributes to the overall composition and sense of story. Camera placement in each of these shots, along with technical settings, was important and helped conveyed a sense of power, softness, character, line, motion, and mood.
For all of my moving water photography work, I carry some essential equipment. The first is a sturdy tripod. Often I am standing in the water and I need a solid base for the camera. All too often I see photographers scrimp on a tripod. It is essential to long exposure waterfall and water work. I use Induro tripods and heads. Singh-Ray Filters are also an essential part of my kit. My filter kit consists of a Singh-Ray 105mm circular polarizer, a Singh-Ray George Lepp 4×6 3-stop solid ND and a Singh-Ray Mor-Slo 5-stop solid ND. These are attached using my 15-year-old HiTech filter holders. I have various filter adapters to cover my lenses. I also use an 82mm Singh-Ray Vari-N-Duo that combines a polarizer with up to 8-stops of variable neutral density. An electronic shutter release is also must. And somewhere in my bag, or in my jacket, is a micro fiber cloth for cleaning off spray and water droplets. I won't go in to my wading gear in this post.
I shoot completely on manual with my exposure setting on evaluative and set for ½-stop increments. For the most part I shoot brackets one stop apart, but there are times when a ½ stop is necessary. Since I use Nikon's and Sony mirrorless cameras, I have to consider slightly different shooting scenarios depending of the camera I am using. With the Sony mirrorless I do not have to worry about mirror lock-up. But this is essential when shooting with other DSLRs to minimize shutter shake. So for the Nikon D810 I shoot with mirror lock up and with a 2-second shutter delay. I also use the 2-second delay with the Sony. When I am situated in fast water I will often use my hand to apply a slight pressure to the tripod to steady it. This technique only works when you have a solid base under the tripod. I refer to the histogram during shooting to make sure I am not blowing out highlights or am so deep in shadows that recovery will be difficult. Remember though that just because you do not have blown highlights that you will have texture in the water (Consider the test scenario I described above). I am always looking to create a master file that contains all of the shadow and highlight detail. From there I can make decisions about the final image during processing.
Thanks for stopping by today! RHC