How to do a long exposure in photography

If you love photography, whether while traveling or in everyday life, chances are you’ve already heard the term long exposure. It’s one of the most popular techniques for creating beautiful images, especially landscape photos. Since I’m personally very fond of this kind of technique, I’ll explain in this article, mainly with a DSLR in mind, how to do a long exposure, also known as long exposure photography. If you want to learn this type of photography, for example with waterfalls, you’re in the right place!

Rest assured, you don’t need to be a professional photographer to take long exposure pictures. However, to capture beautiful long exposure photos, you’ll need to master at least the basics of digital photography: aperture, shutter speed, ISO sensitivity (the exposure triangle) and depth of field. Understanding overexposure, underexposure and exposure correction will also help you improve quickly with this technique. To go even further, you’ll also need a few editing basics in image-processing software, such as noise reduction, white balance, histograms and so on. I’ll cover these ideas gradually in the photography basics section.

You’ll probably need a few tries to learn the technique and reproduce the atmosphere of the scene as faithfully as possible. As we’ll see at the end of the article, some post-processing will almost always be needed for a long exposure shot. So, let’s get started.

So, long exposure: what is it? How does it work? What is it used for in photography? How do you do a long exposure in photography? How do you capture a long exposure of a waterfall? How can this technique improve your photos? I’ll explain everything in detail.

Long exposure is a photography technique that adds an artistic feel to your images. Its main purpose is to slow down, or even completely blur, a moving subject. This could be people, clouds, cars, waterfalls, a starry sky, moving seawater and so on.

Most photographers use this technique in landscape photography, especially with the sea, waterfalls and clouds, three subjects that lend themselves perfectly to it. The idea is to give your photo a more original look and, in a way, create a stronger atmosphere by using a slow shutter speed on a moving subject.

In this article, I’ll explain how to achieve a long exposure in photography, what camera gear you need to use this technique, which subjects work especially well, and how to take long exposure photos depending on the shooting conditions (daytime, nighttime, sunset/sunrise).

Finally, this technique can also be useful from a purely technical point of view. Sometimes you simply don’t have enough light, and a long exposure is the only way to get a sharp picture. This is often the case, for example, in night photography, when the available light is extremely limited.

Before explaining the technical side of taking a long exposure shot, let’s quickly look at the subjects that work particularly well with this technique. As explained in the introduction, to get an artistic effect with the long exposure technique, you need to choose moving subjects, whether they move slowly or quickly. Here are the most popular ones:

• The sea: it is one of the most photographed subjects in long exposure photography. By the seaside, you can vary the effect of the long exposure so that it is more or less pronounced. You can either create a slight motion blur or completely smooth out the sea with a milky, misty effect using a very long exposure time, sometimes several minutes. The result is much more interesting than a frozen, static sea.

• Rivers: another perfect subject, well suited to this technique and capable of producing beautiful artistic effects. Ideally, choose areas with plenty of movement, such as eddies or water flowing around rocks.

• Waterfalls: this is the subject many landscape photographers spend a lot of time on, myself included. Just like with the ocean, the long exposure effect can be more or less pronounced depending on your exposure time. This is typically a subject where freezing the scene tends to produce much less appealing results. The misty, soft effect created by a long exposure can be superb, and the final image will usually be much stronger. Want to know more about waterfall photography?

• Clouds: the effect is especially visible when clouds are moving quickly. So remember to observe the scene and shoot at the right moment. A very long exposure is often needed to achieve this type of image.

• The stars: the long exposure technique can create beautiful star trails with very long exposures. However, this technique requires practice and solid technical skills. Other photographers enjoy taking long exposures of the Milky Way.

• Light painting: slightly apart from traditional photography, long exposure can create very nice effects by combining people and light.

• Carousels: this is certainly not the main use of long exposure, but like any moving subject, carousels can produce very beautiful artistic photos (for example, a Ferris wheel at a fairground). Don’t expect to nail the photo on your first try, though! You see this quite often in urban landscape photography.

• Road traffic: another perfect subject for long exposure. You can create beautiful yellow and white trails from moving vehicle headlights.
• Fireworks: also an excellent subject that lends itself very well to long exposure.

To understand how to shoot a long exposure, keep in mind that the technique will vary depending on the shooting conditions.
The essential point to understand is the following: to do a long exposure and get this kind of result, you need to increase the exposure time of the photo. By slowing down the shutter speed, you create that blurry, milky effect on the sea, or that sense of movement in a waterfall.

So how do you increase the exposure time in a photo? You have three main options in your camera settings. This is the classic trio: aperture, ISO, shutter speed. These three settings are directly linked to one another. Each of them will be covered separately in dedicated articles.

• The aperture: to increase the exposure time, you need to close the aperture, which means using a higher f-number. As a reminder, the larger the number, the smaller the aperture (yes, it’s not very intuitive at first!). The difficulty is that the more you close down the aperture, the more diffraction appears, which can reduce image quality. In general, we try not to go much beyond f/11 to f/14. Even then, in many shooting conditions, this will not be enough to achieve the desired effect, meaning the exposure time still won’t be long enough.

• ISO: if you still don’t get the long exposure effect you want after closing the aperture as much as reasonably possible, you need to adjust the ISO sensitivity. Here again, the goal is to increase the exposure time. Normally, we tend to raise the ISO when there isn’t enough light so we can shoot faster. Here, we do the opposite. We lower the ISO as much as possible to slow down the exposure (ISO 100, or even ISO 50 on some DSLRs).

Now let’s quickly talk about shutter speed. You might be wondering: why not just slow down the camera’s shutter speed? In some conditions, that will be enough. But in the middle of the day, if you set a 5-second exposure, for example, your photo will be completely overexposed (“burned,” as we say). Simply put, too much light will reach your camera. In bright conditions, such as full sun, your DSLR cannot create a long exposure without an ND filter (neutral density filter).

So, to understand how to do a long exposure, the goal is to work with these three settings. In the next three sections, I’ll explain how to take a long exposure shot in three of the most common situations: daytime, nighttime, and sunset/sunrise. It’s not rocket science, but the technique does require a little practice and understanding.

Even if the shooting conditions influence the technique and the way you do your long exposure, the general principle remains the same:

1. Find the subject you want to capture.
2. Place your camera on your tripod to stabilize the whole setup (this technique is impossible handheld).
3. Pay attention to the composition and framing of the scene. Try to guide the viewer’s eye and frame the scene as carefully as possible.
4. Enable noise reduction on your DSLR, if you have that option.
5. Activate mirror lock-up.
6. Cover your viewfinder to prevent light from entering and creating reflections.
7. Turn off the lens stabilizer.
8. Set your DSLR to remote control mode.
9. Use aperture priority mode, the easiest way to start (Av on Canon and A on Nikon), by turning the dial on your camera.
10. Choose the best settings for the scene: the lowest ISO and usually a small aperture, such as f/11, because in landscape photography we often want a large depth of field.

These steps will be almost identical whether you do your long exposure with or without a filter, during the day or at night. This is the foundation.

For those looking for tips on landscape and travel photography, I’ve written two complete articles on the subject.

To take a long exposure picture during the day, the light is usually so strong that a long exposure will be impossible without using an ND filter, or neutral density filter. For those who are not familiar with them yet, I’ve written two complete articles explaining what an ND filter is for and how to choose one. This type of filter is therefore required, and depending on the effect you want in the photo, you’ll choose the density (opacity) of your ND filter. A third article explains in detail how to use an ND filter for a long exposure, technically speaking, depending on whether your ND filter has a high or low density.

The basic principle is simple: measure the shutter speed given by your DSLR without the filter, then adjust that shutter speed according to the density of your ND filter. The goal is to darken a scene that has too much light, since the ND filter only lets a limited amount of light through depending on its opacity. The rest is mainly practical and technical. Just remember that this accessory is essential for daytime long exposure.

When I talk about low-light conditions, I’m mainly referring to the hours before and after sunset/sunrise (“golden hours” or “blue hour”). By the way, if you’re interested, I’ve written a complete guide to taking beautiful sunset pictures (tips, technique, settings, equipment, etc.). To understand how to do a long exposure during these hours, there is one thing to keep in mind. You have two options:

Optimize your DSLR camera settings as much as possible

Unlike long exposure in the middle of the day, which usually requires an ND filter, long exposures at the end of the day or early in the morning can be possible by adjusting only the camera settings, up to a point.

All you need to do is:

• Repeat the steps mentioned above.
• Choose a small aperture to increase the exposure time (for example, f/11 to f/16).
• Lower the ISO as much as your camera allows (ISO 50 at the lowest on some digital cameras).

With these settings, your camera will show you the shutter speed it will use to take the picture (press the shutter-release button halfway to get the information). It’s up to you to decide whether this is enough for a long exposure. Depending on the effect you want, this technique may not be sufficient, with the DSLR showing something like 1/5 sec to 1 or 2 seconds. If you want a more pronounced long exposure effect, you’ll need to use an ND filter to reduce the amount of light even further, which brings us to the next point.

In any case, if the conditions are right, you can consider shooting and doing a long exposure without a filter here.

Use an ND filter to reduce exposure time

This brings us to the second option. I’ve written an article on choosing an ND filter, which you can refer to. To keep things simple, if you want a slightly longer exposure, choose a low-density ND filter (ND8 to ND64). On the other hand, an ND400 or ND1000 filter will allow you, for example, to give the sea a completely milky effect. You can then choose between several types of filters, either with a filter holder or screw-on models.

As a reminder, here is a table showing the shutter speed without a filter and the equivalent exposure times with different ND filters and opacity levels.

Be careful, however, not to use filters that are too dense (ND400 or ND1000) in low-light conditions, as this can lead to exposure times that are much too long. Unlike what we discussed above, you would then be forced to open the aperture (choose a larger aperture) or raise the ISO to compensate for an exposure time that is too long, which is the opposite of what you normally want to do for a long exposure.

For example, if your camera gives you 1/4 sec without a filter, adding an ND1000 filter at that moment gives you a 4-minute exposure, which is not always necessary! This is why I very often recommend choosing an ND64 filter (6-stop light reduction) for sunset and sunrise.

This is the simplest shooting condition for long exposure. Since the light is already very low (normal, it’s night!), you won’t need an ND filter for long exposure photos at night.

All you have to do is follow the steps mentioned at the beginning of this article and take your photo. However, you may sometimes need to use manual focus depending on your camera’s ability to focus in the dark (in other words, turn off autofocus).

Another point I already mentioned at the beginning of the article: at night, long exposure is often one of the only ways to take a sharp picture.

Well, I hope you now understand how to do a long exposure at night. It really is the simplest case.

Let’s quickly review the gear required to do a long exposure. You will need at least a minimum amount of equipment for this technique:

• The tripod: this is the essential piece of gear for long exposure, even though I have to admit that I’ve already taken a few long exposures by placing the camera on a wall or something similar (but it is far from perfect and often ends up slightly blurry). Keep in mind that the slightest movement will result in a blurry picture.

You can refer to the article on how to choose a tripod and which criteria to consider. Your choice will mainly depend on the weight of the gear you need to mount on the tripod, and of course on your budget. Stability is the key word here.

• A remote control: there are several models, including wired and wireless remote controls. If you press the shutter-release button directly on your camera, it creates tiny vibrations that can reduce the sharpness of your photo. I’ve personally owned this Canon remote control for several years, and I’m very happy with it.

It’s better to use a remote control for long exposure photography. Another option is to use your camera’s timer (10 seconds).

• Extra batteries: this is something people sometimes forget. Long exposures tend to drain the battery much faster than usual. So if you’re planning to shoot long exposures in the evening or at sunrise, I recommend carrying at least one spare battery, in addition to the fully charged one in your camera.

• An ND filter or neutral density filter: this is discussed throughout the article. To choose your ND filters, you can refer to my article on how to choose an ND filter. In bright conditions (daylight), and even sometimes in low light, they are one of the essential accessories for long exposure.

Here are some ND filter references (screw-on or square filters with a filter holder) that I still use for my long exposures.

• An exposure-time app or calculator: yes, because unless you’re very good at mental math, you’ll need one. There are many apps that do this very well. You can also find ready-made tables online showing shutter speeds with and without filters. Even better, if you want to make sure you understand how it works, you can create your own table in Excel (that’s what I do). You can print it, laminate it and keep it in your camera bag.
• Finally, a polarizing filter screwed onto the front of your camera lens can be useful for long exposure photography. This photo filter can be used occasionally to add contrast and saturation to the scene while shooting. However, watch out for vignetting as soon as you start stacking more and more filters.

These are the essential accessories for long exposure.

Last point in this very detailed article (too detailed?): post-processing long exposures. In most cases, you will indeed need to work on your long exposure photos in editing software. I’ve been using the well-known Adobe Lightroom for years, and more recently DXO software as well.

So why edit your photos? For three main reasons:

• White balance: depending on the type of ND filter used, a slight color cast may appear in the photo. Simply put, the colors in your photo may not reflect reality. They may be warmer or cooler. This can be easily corrected in software.

• Sensor spots: long exposure tends to make spots more visible in your photo. These are actually dust particles already present on your sensor, and they become visible in long exposures as soon as you close down the aperture too much (from around f/11). This is very easy to fix in editing software.

• Noise correction: even if you have enabled noise reduction, your photo may still have a slight texture. You can easily reduce this in post-processing.

I’ve now reached the end of this article explaining how to do a long exposure. You can refer to the more detailed article to understand how to use an ND filter (neutral density filter) to technically perform a long exposure.

If you have any questions about this article, don’t hesitate to ask them in the comments! Keep in mind, however, that it will take several tries, with plenty of trial and error, before you really succeed in capturing your first good long exposure shot. At first, your photo may be too dark, too bright or blurry… It can be a little frustrating when you’re learning long exposure photography, but once you get used to it, everything becomes much smoother, or almost. To help you with your first attempts, feel free to read the article on how exposure works in photography.

So, are there any photographers who don’t love long exposure?

See you soon for a new photo article,

Written by Sylvain PONS

I've been passionate about photography since 2010, learning as I went along. Today, I dedicate myself to guiding others in their choice of camera gear and sharing a variety of tips to improve their photography skills.

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