Water is a hugely versatile photographic subject. From tiny droplets to vast oceans, it offers unlimited creative potential and plays its part in virtually all natural world images in some way, shape or form. It’s also the perfect subject on which to experiment with longer exposures – anything slower than l/30sec – and manipulate how the water appears in the image.
First thing first – Protect your lens
Cascading waterfalls are a classic subject to practise on – the longer the exposure, the more the water appears as a smooth cotton wool-like blur. You could also practise on a running tap and achieve the same effects in the comfort of your own home – it just depends how bad the weather is!
If you opt for the outdoor option, be aware of the health hazards. Wet rocks are great to photograph but can also be incredibly slippery so take care, and always wear a sturdy pair of wellies if you plan on getting close to the action.
Splashing water hitting your lens can be a nuisance so make sure your lens hood is in place to minimise the spray, and pack a lens cloth to wipe away any drops – the closer you get, the more you’ll need to do this. There’s nothing worse than watery blobs ruining your shot!
The best time to shoot water outdoors is just after heavy rainfall, when streams and rivers are high and waterfalls are looking their best. This will give you the perfect subject to work with.
How to photograph moving water – Shutter speed for creative blur
Composition is the glue that holds all photos together. Whether you’re using the rule-of-thirds, lead-in lines, foreground interest or breaking the rules with a centrally composed subject, composition is always at the heart of the shot.
Camera setting: Shutter speed 118 sec at f/18 - ISO 100
Composing shots of moving water follows the same traditional conventions of any landscape photo, so use the rule-of-thirds as a guide and try to incorporate other devices if the scene allows for it.
Remember that for the rule-of-thirds to work you have to imagine the viewfinder is split into nine equally-sized rectangles by two vertical and two horizontal lines. The subject should be placed on one of the four points where these imaginary lines would intersect.
The ideal visual elements to place at these points are solid objects like rocks or trees. Having pin-sharp elements such as these in the photo helps to emphasize movement as the water blurs past, but most importantly it helps to anchor the shot to reality by showing sharpness in the scene.
Focusing only on water and allowing it to blur would result in an abstract photo, and that’s not what we’re aiming for.
Camera setting: Shutter speed 8 sec at f/20 - ISO 100
With composition under control, exposure is the next key element of taking a long exposure water shot. ISO and aperture are important, but the control that will be your best friend is shutter speed. Using ISO and aperture effectively will help you to achieve the right shutter speed for the job.
We have just looked at how a slow shutter speed is the ideal way to make running water, or indeed any moving subject, appear blurred. The speed the water is moving, and how smooth and milky you want the water to look will determine how slow your shutter speed needs to be. Next, we need to look at how to achieve a slow shutter speed using aperture and ISO, and how to do that on your camera.
Choose the minimum aperture
The aperture is a variable hole inside the lens that allows light into the camera and onto the sensor. The smaller the aperture, the less light can pass through, which means you can have a longer shutter speed to achieve the right exposure.
In other words, a big hole open for a short amount of time can give the same exposure as a small hole open for a long amount of time.
Camera setting: Shutter speed 2 sec at f/5.6 - ISO 100 (ND-10 - see below for filters)
In this case, we want a long shutter speed. If we use the smallest aperture (largest f/ number) available, this will let the minimum amount of light possible into the lens and requires the shutter to be open for longer to achieve a balanced exposure.
As in the photo above, with an aperture of just f/5.6 I was able to have a 2 seconds shutter speed, however I achieved that using an ND-10 filter (see more on filters below)
In the photo below I used an aperture at f/16 (quite a small hall) for a 2 seconds exposure. That was enough to have a silky effect on the water.
Set the aperture
With your camera set securely on a tripod, switch to aperture-priority mode, marked by A or Av on the mode dial. Now change the aperture to the largest f/number available, which on most lenses is around f/22-f/32.
This will allow you to achieve the slowest possible shutter speed for the amount of light available. If you would prefer a faster shutter speed, simply increase the size of the aperture
Camera setting: Shutter speed 2 sec at f/16 - ISO 100
Select a low ISO
When shooting moving water, usually a low ISO is used. This will allow to have an higher shutter speed, even if you’re shooting with the smallest aperture.
A setting of ISO 100 is the best place to start, as this is where images have the best quality and the least digital noise. The method for changing the ISO varies from camera to camera, so check your manual for instructions.
Here is how I do it
I set ISO to 100 (or 200). I shoot in Shutter Speed mode (S/Tv) and I select the time. This depends on the water. It may be just 2-3 seconds, with fast moving water, or up to 30 seconds, with slow moving water. The aperture will be decided by the camera.
I try to select as many as seconds for the camera to have an aperture of F/9 to f/16 (this is the range with the sharpest photos)
If I have to go over 30 seconds than I select BULB mode (On Fuji cameras it is 60 seconds)
ND filters for long shutter speeds
Using the smallest available aperture and the lowest possible ISO will give the slowest shutter speed your camera is capable of in a given situation. But on a bright day the slowest shutter speed you can achieve might only be l/20sec, which may not be slow enough to give you the blurred effect you want.
Unfortunately, without any extra kit your camera is simply incapable of letting less light in. What is the solution? A neutral density (ND) filter.
Camera setting: Shutter speed 67 sec at f/22 - ISO 100 (filter ND 10)
This is effectively a piece of tinted glass that screws to the end of the lens to limit how much light can enter. This means you’ll need a slower shutter speed with the filter on to get the same exposure as when it’s off.
ND filters come in a range of strengths to block the light to varying degrees. I really suggest to invest in filters with at least the same quality as your lens. No much point to have a $1000 lens and a $15 filter that will decrease the quality of your photo
The highest the ND number is, the darkest is the filter itself. For example a ND 10-Stop Filter provides 10 stops of exposure reduction and it will be so dark that you will not be able to see through it. You have to compose and focus prior to the filter installation
Unfortunately some of these ND filter can add colour cast to your photo, just be aware