Few natural subjects are as breathtakingly beautiful as waterfalls. Even tiny waterfalls--such as rapids in a stream--take on an almost otherworldly beauty when photographed as the inherent motion of the water is captured in a still frame. Unfortunately, snapshots rarely capture the magic, because they're shot with a smartphone or some other camera set on automatic exposure mode. If you want to capture the blurry, smooth excitement of a waterfall, you'll need to experiment a little with your camera's advanced settings.
Slow shutter speed
You've no doubt seen two kinds of waterfall photos. The first kind is easy to take: Just point your camera at the water and press the shutter release. The camera's fast shutter speed will tend to freeze the water in place, and you'll get an unremarkable photo of the scene. There's nothing wrong with a waterfall photo like that, but you can do better. The other kind of waterfall photo? A slow shutter speed blurs the torrent into a majestic fog of water. That's what we'll talk about here.
Good news: There's really only one trick you need to know when it comes to capturing these waterfall photos. You need to shoot with a slow shutter speed. Any shutter speed slower than about a quarter second will do, but photographers commonly use a variety of speeds up to about 2 seconds to get that creamy blur.
So how do you get a shutter speed like that? The easiest way is to dial your camera to Aperture Priority mode and then set the shutter speed. Make sure that the camera's ISO is set to its lowest value (probably 100) so you have the best chance of getting a longer shutter speed in daylight.
Stabilize your camera
Of course, if you're shooting a slow shutter speed, you can't hold the camera in your hands and expect to get a stable shot free of shake and blur. You'll want to mount the camera on a tripod of some sort, or at least find a stable place to rest it so it won't move during the exposure. It's a really good idea to turn on the self-timer mode and then let go of the camera entirely, so you don't accidentally shake the camera while the shutter is open.
And if all you've got is a smartphone, you're in the game as well. It's true that you won't find advanced shutter speed controls on any major smartphone, but that's okay; there's an app for that. On the iPhone, try Slow Shutter Cam ($1). Android owners, check out Camera FV-5 (free). Remember, though, that you'll want to keep your phone as still as possible for these time exposures, so set it down or lean securely against some sort of support. And if you're really serious, don't forget that you can get a $30 tripod for your phone.
Watch out for the sun
Since great waterfall photos rely on slow shutter speeds, you might run into a problem taking pictures in daylight: It's just too bright out to make the shutter speed that low, and your camera might default to shutter speeds too high to blur the water.
So it's no surprise that you'll find that the best waterfalls photos happen deep in the woods, where trees help shade your subject from direct sunlight. You can also shoot early in the morning or late in the afternoon, when the sun is low in the sky.
If you're shooting with a DSLR, there's another option at your disposal: You can purchase a neutral density filter and affix it to the front of your lens. Neutral density filters come in a variety of strengths and follow a standard notation: ND2, for example, reduces the light by half, while an ND4 filter admits a quarter of the light. If you plan to do a lot of slow shutter photography in daylight, you might carry both an ND2 and an ND4, and use whichever one you need. You can even use them both at once for the equivalent of an ND8.