Long exposure photography has quickly grown to become one of my favorite styles of photography and it’s quite clear by looking through the images I’ve captured the last few years. More and more images use a shutter speed slower than half a second and it’s further between the handheld shots.
Which ND Filter to use?
One of the reasons I’ve grown to become such a big fan of long exposure photography is that it opens so many doors. You’re much less limited in your work and you have endless of options when it comes to how you want your image to look. However, it’s exactly this benefit which also becomes a challenge for many: how do you choose the right shutter speed and ND Filter?
I don’t believe that there’s one correct shutter speed or filter when it comes to landscape photography. A big part of the creative process is to do what you prefer and go for the look you want to achieve. However, if you want to be able to achieve the look you want, you’ll also need to know how to get there and that’s why it’s important to understand how each of the different ND filters will affect your image.
In this article, we’ll look at how each of three different (three, six and 10-stop) ND filters will affect your image and in what scenarios they are each most beneficial.
3-Stop ND Filter
If you’re familiar with Neutral Density filters you may already know that a 3-stop filter won’t have a huge impact during brighter hours. Compared to the six and 10-stop filters, the 3-stop is not particularly dark and it won’t allow you to use those extremely slow shutter speeds of several minutes.
That being said, the 3sStop ND Filter remains one of my personal favorites. I particularly enjoy working with it when photographing waves from a low perspective.
The picture above was taken a couple hours after sunrise but due to the sun’s low position on the Arctic sky, it still wasn’t daytime-bright outside. However, without using a filter, the shutter speed would have been too quick to capture the motion I wanted in the water. So I knew that a 3-stop ND filter would do the job. Using it allowed me to lengthen the exposure time to 1/3rd of a second, which was just enough the get some motion in the rushing waves and to achieve the look that I wanted for this shot.
Had I used a 6-stop ND filter instead, the image would look quite different since the longer shutter speed would blur the water and lose the texture that I was aiming for.
6-Stop ND Filter
As the name indicates, a 6-stop ND filter lets you lengthen the exposure time by six stops (not six times – six stops is 2x2x2x2x2x2 = 64 times). If you’re already using a relatively slow shutter speed due to the sun’s low position in the sky, this means that you can achieve a very slow shutter speed when using this filter.
For the image above, I used a 6-stop ND filter to blur the water and create an overall softer feel to the scene. Using the filter allowed me to lengthen the exposure time to 15 seconds, which was just enough to blur the water and create some motion in the sky. As you can see, however, the iceberg in the foreground is already blurring out when using a 15-second shutter speed.
Had I instead used a 10-stop ND filter and an exposure time of a few minutes, all the ice would be blurry due to them constantly moving. On the other hand, a 3-stop ND filter wouldn’t have allowed me to slow down the shutter speed enough to blur the water and I wouldn’t be able to achieve the look I wanted.
10-Stop ND Filter
The 10-stop ND filter is perhaps the most popular filter for many who are just getting started with long exposure photography. The effect is extremely visible and the images created with it can grab attention right away. Even though there are darker filters available (such as a 16 and 20-stop), the 10-stop filter is often what people think of when talking about long exposure photography.
The image above is a typical example of how a 10-stop ND filter can create a surreal look to the image. With the filter placed in front of my lens, I was able to use a shutter speed of four minutes to completely blur the lake and get a soft, dramatic look in the sky as the clouds were dragged out.
While it does require some more planning and patience than the other two filters, it is also the one that has the biggest visual impact straight out of the camera.
Choosing the Right One
As I mentioned earlier in this article, there isn’t necessarily one correct filter that you should use. Instead, you should be aware of how the different filters will affect your image and then choose the one which will get you closest to your envisioned image.
Long exposure photography opens many doors and gives you several new creative elements to work with. As with anything else, a big part of this technique is trial and error but as you continue learning you’ll also begin seeing what you need to do in order to capture the images you want.
If you want to learn more about Long Exposure Photography I’ve shared everything I know in my eBook The Ultimate Guide to Long Exposure Photography. This eBook is for those who are ready to take their images to the next level and expand their creative vision.