Convey motion in a still

Adam Waring uses a variable neutral density filter to slow down shots just enough to convey a sense of movement

Capture movement with a variable ND

Windmills are among the most picturesque man-made structures that can be found on the landscape. But these oncefunctional buildings, which used the power of the wind for anything from draining waterlogged land to milling flour, are now relics of a bygone era, and as such are mostly static shells, whose sails turn no more.

But that’s not the case with Wilton Windmill… It’s been lovingly restored and preserved in the Pewsey Vale of Wiltshire. It also still uses the power of the wind to grind grain into flour in the age-old tradition – sails turning under the power of the wind. Which begs the question: how do you convey this sense of movement in a still?

Using ND filters to get long exposures can turn the churning sea into a milky blur, or moving clouds into painterly streaks and, in the same way, can be used to blur the moving elements in your scene, helping convey a sense of movement. However, rather than exposures that are several seconds – or minutes – long, we want an exposure that’s typically just under a second; enough to add a hint of blur to the spinning sails.

You need to strike a careful balance. If your exposure is too short, it’ll just look like the sails are out of focus, rather than moving, but too long and they become an indistinguishable mess – or even disappear altogether. This is where a variable ND comes in, as we have complete control over just how dark the filter is, we can control our exposure time precisely to show the sense of movement we want without compromising our other camera settings.

Compose your scene

Set your scene as you would any landscape shot, using the rule of thirds. As the windmill is our main subject we placed it on a third line towards one side of the frame and placed our horizon along the bottom third. In an effort to show the movement clearly, we ensured our windmill was reasonably large in the frame.

Go-to settings

For total control of your settings, shoot in Manual. Set a narrow aperture, such as f/11 – this will not only ensure that you have a good depth of field, so your scene is sharp from front to back, but will slow down your exposure, too. Set a low ISO for top quality – we went for ISO100 – and dial in the shutter speed suggested by your exposure meter. In our case this was 1/160 sec.

Attach the filter

The filter screws onto the front of your lens. Before the shoot, we weren’t sure whether we’d be using our wide-angle lens, which has a filter thread diameter of 82mm, or our 24-70mm standard zoom, which has a diameter of 72mm. The Syrp filter we used has an 82mm thread, but comes with step-up rings for attaching to 72mm and 77mm diameter lenses as well.

Darken the glass

A variable ND is constructed from two sheets of polarized material, the outermost of which rotates. Turn this from the Min to Max position and the filter gets gradually darker. Markings on the filter show the rough number of stops. The exact shutter speed you’ll need for the shot to look ‘right’ will depend on the speed the sails are turning. For our shot 1/4 sec was right.

Take the shot

Shooting at such a slow shutter speed will require a tripod to avoid camera shake. A remote shutter release is also desirable to avoid ‘jogging’ the camera as you press the button – at these sorts of shutter speeds the effect will be very pronounced. You’ll need to time the shot so that the sails form an ‘X’ shape for the best composition – and for this reason, using the 2-sec self-timer rather than a remote release is impractical.

Alternative tricks

What if you don’t have a variable ND? 10-stop ‘big stopper’ style ND filters are all the rage nowadays, but will slow down your exposure far too much. You can counteract the effect of the filter and increase your shutter speed by simply increasing your ISO – it’s a compromise, but will get you the shot. Some Nikons have a slower base ISO than 100 – such as our Z 7’s ISO64 – and even slower if you delve into your camera’s ‘Lo’ settings. A polarizing filter at maximum polarization is good for a couple of stops, too.