Long exposure photography – how to blur water

Long exposure photography is becoming increasingly popular. Many landscape photographers have extreme Neutral Density (ND) filters, enabling them to blur water to the point that it looks like mist. It is a great way to create minimalist fine art photography compositions – simplifying a scene by smoothing out details. In the rush to use 10 stop ND filters, sometimes people forget that a shorter exposure (albeit still a long exposure!) can create interesting effects as well. Sometimes, blurring water enough to create a subtle sense of movement can be very effective too.

Equipment needed

Long exposure photography needs the camera to be kept very still. This means that you can’t really shoot handheld. So, make sure you secure your camera using a good tripod. If you don’t have a tripod, then look for flat, solid surfaces where you may be able to put your camera instead. If possible use a cable or remote shutter release. It is important that the camera is not still wobbling and settling down when the shutter opens. Pressing the button manually tends to wobble the camera. If you don’t have one of these releases, then you can use the self-timer on your camera to give it a few seconds to stabilise.

You need a camera that allows you to control your settings. A DSLR or similar (e.g. CSC or bridge camera) is normally best. Ideally, you will need to control aperture, shutter speed and ISO.

ND filters – to enable you to keep the shutter open longer it is very helpful to have some ND filters. You may wish to use graduated ND filters as well to balance the sky with the foreground. Reverse grad ND filters are great for sunrise/sunset when the brightest spot is actually on the horizon. For a really extreme long exposure effect a 10-stop ND filter is ideal – I use a B&W screw on 10-stop. You may also want something less strong such as a 4-stop. A 2-stop filter can be handy, but you may find that a polariser does the job just as well. Polarisers tend to reduce the light by around 2-3 stops. (Jargon buster – see article on what is a stop in photography)

Eyepiece/Viewfinder Cover – this is not the most obvious piece of kit, perhaps, but it is vitally important for long exposure photography. By blocking the viewfinder, you stop stray light interfering with your image. Without it, you will often find bright bands across the image, ruining your photo.

Composition

Some long exposure images need you to think differently about composition. If you are turning water to mist using a very long exposure then it is often helpful to think in very minimalist terms. You are smoothing out the water to simplify the scene. So, make sure that your focal point is obvious to the viewer and that the image isn’t otherwise too cluttered. These images can often work well in black and white, which further reduces distractions. For these images to be really powerful, however, you need a very strong, simple composition. Try using just a few rocks with the water or a groyne or breaker or pier, for example. Some solid, static element provides a good contrast to the movement or blur.

Blurring water with long exposure photography

Sometimes in landscape photography you don’t want to see the details of waves or freeze droplets of water in the air. Instead, you may want to suggest a feeling of motion by blurring the water a little. Or, you may want to turn the water into a milky or misty texture by blurring a lot. By practising a few techniques, you can gain control over how the water will appear in your final image. From a subtle blur which leaves waves still distinguishable, to a smoother texture, all the way to mist, these can all be achieved with the right settings. Here are some tips on how to go about it:

• To blur the sea slightly to create a sense of movement in waves, but still keep them distinct, you will need a shutter speed of around 1/30 to 1/3 second. The amount of blur will also depend on the speed that the water is flowing at. This sort of setting is often good for waterfalls or rocky streams as well.
• For blurred water with some hint of movement but little definition in the waves you can use a shutter speed of around 0.5 to 15 seconds, depending on the conditions.
• For an effect closer to a misty texture you will need an exposure ranging from around 20 seconds to several minutes.
• To achieve the shutter speed you want, you may need to use an ND filter to cut out some of the available light if it is a bright time of day.
• You can shoot either in shutter priority mode (S or Tv) or in Manual mode (M). Shutter priority mode will choose the aperture value for you. If you prefer to have complete control over all your settings use manual instead.
• I prefer to set the ISO and aperture in aperture priority mode (A or Av) and see what shutter speed the camera recommends. I then switch to Manual. Then, in order to achieve the desired reduction in light to give a longer shutter speed I may add ND filters or slightly tweak the settings. Remember that each time you want to halve or double the shutter speed is one stop. So, for example, to get from 1/120th second to 1/15th second is 3 stops. You might use a 3 stop filter (or a 2 and a 1) or a 2 stop filter with a 1 stop reduction in aperture or ISO, for example.

Summary:

• Use a tripod, eyepiece cover & cable/remote release if possible
• ND filters can help achieve longer exposures
• Think about how blurred you want the water to be
• For extremely long exposures, consider a minimalist composition
• Keep the ISO low and shoot in Manual or perhaps Shutter Priority

I hope that this has inspired you to try long exposure photography and to play around with blurring water using long exposures – and not just with 10-stop filters! The results can be a little unpredictable as you never know precisely what water will do. So if you don’t get what you want to begin with, keep trying different settings and time your shots differently (e.g. just before waves break, etc.). Above all, as usual, have fun!

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© Joe Lenton, April 2015