Posted on October 18, 2020
“Natural” is a moving target that shifts with perspective. Humans experience the world as a 360 degree, three-dimentional, five-sense reel that unfolds in an infinite series of connected instants that our brain seamlessly assembles as quickly as it arrives. But the camera discards 80 percent of the sensory input, limits the view to a rectangular box, and compresses all those connected instants into a single, static frame. In other words, it’s impossible for a camera to duplicate human reality—the sooner photographers get that, the sooner they can get to work on expressing the world using their camera’s very different but quite compelling reality.
Despite the creative opportunities the differences between human and photographic vision offers, many photographers expend a great deal of effort trying to force their cameras closer to human reality (HDR, focus blending, and so on)—not inherently wrong, but in so doing they miss opportunities to creatively reveal our natural world. Subtracting the distractions from the non-visual senses, controlling depth of focus, and banishing unwanted elements to the world outside the frame, a camera can distill a scene to its overlooked essentials, offering perspectives that are impossible in person.
Motion is one thing that an image “sees” differently from you and me. But working in a static medium doesn’t mean photographers can’t convey motion, or use motion in a scene to creative effect.
One question I’m frequently asked is, “How do I blur water?” And while there’s no magic formula, no shutter speed threshold beyond which all water blurs, blurring water isn’t that hard (as long as you use a tripod). In fact, when you photograph water in the full shade or cloudy sky conditions I prefer, it’s usually more difficult to freeze moving water than it is to blur it.
The amount of moving-water blur depends on several variables:
Of these variables, it’s shutter speed that gets the most attention. That’s because focal length and subject distance are compositional considerations, and we usually don’t start thinking about blurring the water until after we have our composition. To achieve a longer shutter speed without overexposing, you need to reduce the light reaching (or detected by) the sensor. There are several tools at your disposal, each with its own advantages and disadvantages:
Other motion blur opportunities
Motion blur opportunities aren’t limited to crashing waves and rushing whitewater. For example, I love using long shutter speeds to smooth the undulations and chop on the surface of an ocean, lake, or flowing river. And a particular favorite approach of mine is blurring something floating atop moving water, like dots of foam or autumn leaves. And my favorite time and place for this is each autumn at Bridalveil Creek in Yosemite. Here, beneath Bridalveil Fall and shaded by Yosemite’s towering granite walls, are countless pools surrounded by colorful trees and fed by tumbling cascades.
The motion of the cascade’s entry and exit creates arcs and spirals of motion in the pool, punctuated by small pockets of stillness near the perimeter. Leaves fall from the trees and land on the water, or flow down from upstream, congregating on the pool’s surface. Some just make a single arced pass before continuing downstream, others join a circular dance that can last for hours. It’s usually impossible to see any organization to the pool’s motion without something floating on the surface, but a long enough exposure with leaves or floating foam will reveal a distinct flow pattern.
After finding a pool adorned with drifting autumn leaves, I set up my tripod and camera, find a composition, and dial in a shutter speed measured in seconds. Depending on the speed of the circulation, sometimes 10-second shutter speeds are enough, but usually I try to go to 20 or 30 seconds. With the help of a neutral density filter, I’ve gone as long as 3 minutes (and maybe longer).
Once the blur patterns reveal themselves in my images, I tweak my composition and shutter speeds accordingly. Because there are usually many leaves, and each leaf takes a slightly different path depending on its size and interaction with other swirling leaves, each click results in a unique image. I’ll sometimes work a single composition for 15 or 20 minutes, collecting as many motion patterns to choose between as possible, before moving on to another composition or scene.
The image I’ve shared here is a 15-second exposure, captured at Bridalveil Creek in 2009. Because this location is always in full shade, and this was a cloudy day, the scene was dark enough that I could slow my shutter enough with just a polarizer. I’ve always felt like a polarizer is essential to remove glare from the water, leaves, and rocks in these scenes, but at the time I always had to decide between a polarizer or neutral density filter—I couldn’t do both. (I now have a Breakthrough 6-stop darkening polarizer that achieves the best of both worlds.)