Shooting waterfalls is fun, easy and can reward you with some stunning images!
The Huay Sae Luang waterfall in the Inthanon mountains, close to Chiang Mai, Thailand
Nikon D750, 20mm f/1.8G, circular polarizer (acting as a 1 stop ND-filter), f/22, 0.4s, ISO 100
Gear
The only gear really required is a camera, preferably with the option to choose f/stop, shutter speed and ISO manually. A tripod is recommended, but I have seen great photographs of waterfalls shot handheld. A neutral density (ND) filter may help you with the exposure, but there is a digital work around to this as explained below. There are often a water sprays close to waterfalls, so it might come handy with a weatherproof camera and lens.
Lens
The choice of focal length of your lens depends on what you want to achieve. A wide angle lens takes in more of the scene and can help you capture the grandiosity of large falls and it is nice to get close to the foreground for more depth. A longer lens is useful for the more intimate subjects.
I am using the downstream water as a foreground to create depth
The Huay Sae Luang waterfall in the Inthanon mountains close to Chiang Mai, Thailand
Nikon D750, 20mm f/1.8G, circular polarizer (1 stop), f/11, 0.3s, ISO 100.
I used a 35mm lens to create a more intimate study of the puddles, the rocks and the fall
Mae Sa waterfall close to Chiang Mai, Thailand
Nikon D750, 35mm f/1.4G, no filter, f/8, 1/4s, ISO 100
Another intimate shot with a 35mm lens
Mae Sa waterfall close to Chiang Mai, Thailand
Nikon D750, 35mm f/1.4G, no filter, f/8, 1/4s, ISO 100
Shutter speed
The shutter speed determines how the water will appear and the choice is very subjective. A fast shutter speed freezes the motion of the water and it often gives a look that is strange and unnatural. A slower shutter speed gives a smooth and dreamy appearance, but be careful because a too long exposure can result in complete loss of texture in the water.
An illustration of how the water appear with a relatively fast shutter speed of 1/40s appear below.
The Huay Sae Luang waterfall in the Inthanon mountains close to Chiang Mai, Thailand.
Nikon D750, 20mm f/1.8G, no filter, f/4, 1/40s, ISO 100
For large waterfalls, my preferred shutter speeds usually span from 1/8s to 1s, often ending up at 1/4s. Experiment and decide what you like best!
Exposure
So how to get a proper exposure once you determined your shutter speed? You might find that you need to stop down beyond what your lens is capable of. The obvious way to solve this is to apply an ND-filter. Say that you measure 1/4s and f/22 at ISO 100 and your lens can only stop down to f/16. Maybe you even would like f/8 for the optimum sharpness? What to do?
Neutral density (ND) filters or image stackning?
An ND-filter that reduce light by 3 stops would let you use the 1/4s and f/8 at ISO 100. Voila! However, ND-filters are expensive, they can add flare and it can be awkward to work with.
A digital workaround is called image stacking and involves making several exposures that are stacked together later in post processing. For this example, you would set the camera to 1/30s and f/8 at ISO 100 and simply make 8 consecutive exposures and stack them together in for example Photoshop.
There are pros and cons with both methods. ND-filters add gear and complexity to the shoot. It might be difficult to focus with the filter attached, so you need to first focus, apply the filter and then shoot (imagine standing knee deep in the water frenetically wiping your lens of the water spray). Filters can also cause flare .
Personally, I still prefer using filters, because it gives me the opportunity to review the image right away on location. I usually shoot a number of exposures, because the appearance of the water vary slightly between the shots.
Image stacking removes the need for expensive filters and you can vary the effective shutter speed in post by the number of images you choose to stack.
Quality and direction of the light
As with all photography, the quality of light is making or breaking the image.
Waterfalls are often situated deep into the landscape and you might find that they are in the shadow most of the time and when the sun is high, the light may be hard.
Other waterfalls are situated higher up and you get opportunities to shot when the sun is low and cast a warmer and softer kind of light.
The Mae Rim waterfall close to Chiang Mai, Thailand. This waterfall allowed the low afternoon glow find its way thru the branches of the trees.
Nikon D750, 20mm f/1.8G, no filter, f/16, 1/4s, ISO 100
There is no right and wrong, just experiment and decide what you like best.
Other stuff to consider
Long exposures can result in motion blur of foliage. You can fix this problem by taking an extra frame at a faster shutter speed, which freeze the movements. Then you blend the images together in post
Bring rubber boots that allow you wade into the water (just make sure it is safe first!) to get the best possible composition :-)
Bring something to wipe clean you lens in case of water spray or mist. Bring lots of it!
Good luck!