Beginning Photography Long Exposure

How to Use a Neutral Density Filter

(Hinton, WV Railroad Depot)

As a photographer, there are all kinds of tools at your disposal, from lenses and filters to lighting equipment and more. The neutral density filter is one of the more under-utilized tools, but I'd argue that it is one of the most useful pieces of equipment you could have.

Why use an ND filter? The simple answer is that this filter lets you take long exposures in bright lighting. In other words, if you're standing on a sunlit beach, and you want the water to have that smooth effect that you can only get at dusk or dawn, then you'd need a 10-stop filter to help you slow down your exposure. The same goes for waterfalls, clouds, moving people, vehicles or any other brightly lit moving object.

These filters let you do some incredible things – but only if you know how to use them. Here are a few tips that will help you make the most of your ND filter.

1. Set Up the Image First

One of my favorite filters is the 10-stop ND filter. Since then it's so dark, it’s extremely difficult to see through it – unless, that is, you have a camera with a live view that does allow you to see through the filter. If your camera doesn't have this capability, the best way to get around it is to set up the image before you put the filter on your camera. Set the camera up on the tripod and frame the image the way you like it. Go ahead and set the shutter, aperture and ISO settings, keeping in mind that you may need to bracket your exposures in order to get a properly exposed image.

Lastly, make sure to lock the focus on your camera. For most cameras, you can simply bring the image into focus using the autofocus feature and then switch over to manual focus so that the camera doesn't try to readjust the focus once the filter is in place.

2. Choosing the Right Settings

I use the iPhone app PhotoPills to help me get the right exposure settings for the perfect photograph. Shots taken with 10-stop ND filters are always long exposures, which means that you'll be relying primarily on the shutter speed to get enough light to your camera’s sensor. With that thought in mind, feel free to use an ISO of 100 to eliminate noise.

By that token, you can also set the aperture to f/11. Chances are that you'll have some kind of motion blur within the image – water, people or something else. That's what you're trying to achieve. Exceedingly long time exposure will eliminate fast moving objects (as if someone walks through your frame) from the photo leaving milky objects as waterfalls and moving clouds.

Once those settings are in place, you'll only need to experiment with the shutter speed to get the exposure right. That's why I use the PhotoPills App to remove the guesswork when I'm setting my exposure. In many instances (though not all), you'll find yourself using the camera’s bulb setting.

3. Extra Equipment You'll Need

The first, most important piece of equipment that you'll need is a tripod to stabilize your camera. If you’re likely to use the bulb setting, a timer of some sort – a stopwatch or the timer on your phone – will help you keep track of exposure times. You'll also need a remote trigger to fire the camera’s shutter without jostling the camera itself.

If you're taking photos outdoors, then you'll find that a set of graduated neutral density filters is helpful. These filters are particularly effective for landscape shots because you can use them to prevent blown-out skies. If you decide to use a graduated ND filter, put it on your lens before you attach the 10-stop ND filter so that you can line the gradient up with the skyline.

It seems strange to create long exposures in broad daylight, but if you already have the equipment or you're looking for a great new technique, then this is definitely worth a shot. The vast majority of daytime exposures are short by necessity. If you can create long exposures with the sun high in the sky, you'll have the ability to create unusual, interesting images.

About the author

Will Moneymaker

Will has been creating photographs and exploring his surroundings through his lens since 2000. Follow along as he shares his thoughts and adventures in photography.