When you keep your shutter open for an extended period of time, clouds start to look like thin wisps of smoke, bodies of water become opaque, and stars turn into bright streaks of light across the sky. Just the idea that you can transform a landscape with just a few camera adjustments can be empowering.
However, it can be just as frustrating if you don’t know what you’re doing. Long-exposure photography can be challenging because what you see with your eyes isn’t necessarily what your camera ends up capturing.
Thankfully, we have these eight easy tips to help you create images that look out of this world.
If you want to take long-exposure photography seriously, then consider investing in neutral-density (ND) filters. Just think of them as sunglasses that allow you to see better when the sun’s too intense. Technically, their job is to limit the light coming into the lens and lets you shoot with extremely slow shutter speeds even in bright light.
ND filters are not only useful in daytime but also when doing long-exposures at night. If you keep your shutter wide open even for several seconds, you’ll realize that the dark sky isn’t exactly that dark. With ND filters, you can extend your exposure time without the risk of overexposing your shot.
To install an ND filter, all you have to do is screw it onto the filter threads found in front of the lens, and you’re ready to start shooting. Just be aware that lenses come in different diameters ranging from 49mm. to 77mm. The filter has to be the same size as the lens, or it won't fit.
Now that you know how ND filters work, you need to learn how to calculate exposures when using them.
ND filters range from ND2 to ND100000, and they all vary in optical density—or the amount of light they allow to pass. Each filter number corresponds to a certain number of f-stop reduction as shown below:
|Add column header||Add column header|
|ND2 = 1 STOP ND4 = 2 STOPS ND8 = 3 STOPS ND16 = 4 STOPS ND32 = 5 STOPS ND64 = 6 STOPS ND100 = 6 ⅔ STOPS ND128 = 7 STOPS ND256 = 8 STOPS||ND400 = 8 ⅔ STOPS ND512 = 9 STOPS ND1024 = 10 STOPS ND2048 = 11 STOPS ND4096 = 12 STOPS ND6310 =12 ⅔ STOPS ND8192 = 13 STOPS ND 10000 = 13 ⅓ STOPS ND100000 = 16 ⅔ STOPS|
So how does f-stop reduction affect exposure? If you set your camera aperture to f/1.8 and you put an ND2 filter (which has an f-stop reduction of 1) on the lens, it would effectively become f/2.8—precisely one stop lower. The same happens with the shutter speed: if it’s originally set to 1/15 secs., re-adjust it to 1/8 secs. (also one stop lower) once the filter is on.
To help calculate exposure times, you can use apps such as the ND Filter Calculator and ND Filter Timer. They show the normal settings as well as the adjustments you need to make when a filter is attached to the lens.
Note that since you’ll be working with extremely low shutter speeds, using a tripod is necessary.
Long-exposure photography requires you to be comfortable enough to adjust your camera manually. One of the most important manual features that you’ll be using is bulb mode, an invaluable function that allows you to create exposures that last more than 30 seconds.
To access bulb mode, switch to manual mode and adjust the shutter speed with your click wheel until you see the word “bulb” (it usually comes after 30”). Once it’s selected, you can make an exposure however long you want as long as the shutter is pressed. However, using your finger is not recommended because it causes too much vibration—install a cable release, so you can safely trigger the camera without having to touch it.
Since autofocus doesn't work correctly when there isn’t enough light (especially with an ND filter on), you need to adjust your focus manually as well. Set your lens to infinity (marked with an ∞ symbol), then look at the screen and use your zoom-in button (marked with a magnifying glass symbol) to magnify the furthest object you see. If it looks blurry, twist the focus ring until the scene looks sharp.
One of the main allures of long-exposure photography is its ability to capture movement creatively. To make wise use of slow shutter speed, include moving elements—such as clouds—in the scene.
When shooting early in the morning or late in the afternoon with no stars around, look for clouds to make your image appear ethereal. Wait until the sun is low enough on the horizon to add color and contrast to the sky. Depending on the ND filter you use, you can create a photo like the ones you see above and below using an exposure between 30” up to 60” (or more).
If you’re interested in taking photos of stars at night, wait for a clear night without clouds that may obstruct the view. You also may have to look for a location that’s far from the city as artificial lights could affect exposure.
Once you find the right location and your camera is set up, select a wide aperture (f/2.8 will suffice) to allow the lens to let as much light in as possible. To focus, zoom in on a star with the zoom-in button (as mentioned in No. 3) and twist the focus ring until it's sharp.
For a typical image of the stars, limit exposure to just a few seconds (a maximum exposure of 15” should do the trick in most cases); otherwise, you’ll start seeing trails in your image since stars are constantly moving.
If it’s light trails you’re after, then feel free to use shutter speeds significantly slower than 15”. In most situations, an exposure between 30 minutes to an hour would be enough produce streaks, but you can extend the exposure time even more if you want. The longer the shutter is open, the longer the trails.
To replicate the circular pattern you see in the image above, first, you need to look for the North Star. Use phone apps such as Star Map or Star Tracker to find it. Simply point your phone towards the sky, and the app will help you locate it. Once you identify the star, point your camera towards it and start shooting.
In urban areas, one of the most interesting long-exposure experiments you can try is photographing light trails from taillights and headlights of passing vehicles. Just look for a strategic position near a busy street, and set your shutter speed to about 5” to 15” or longer.
The same rule on star trails applies to light streaks: the longer the exposure, the longer the lines. If you set the camera correctly, the resulting image should give you long streams of white and red lights.
One of the most experimental aspects of long-exposure photography is light painting, which is the practice of deploying portable light sources to draw objects in the air. You can use flashlights, LED lights, toys, and even fireworks to create figures that appear to float in space.
So, how does it work, exactly? When the shutter opens, the camera sensor records any bright light in the scene. However, due to the slow shutter speed, objects in motion either turn out blurry or will not appear in the photo at all. You can observe the same principle at work when you photograph moving traffic—you only see their light trails and not the vehicles themselves because they’re moving.
Light painting may seem difficult to execute, but in reality, it isn’t. To start, set your camera to self-timer. Then adjust your shutter speed to the amount of time you need to draw something (30” is usually enough). If you need a longer exposure time, choose bulb mode and ask a friend to press the shutter and keep it open for you (bulb doesn’t work with the camera’s self-timer).
Once you press the shutter and the self-timer starts, immediately get into position. As soon as the camera clicks, start writing in the air. If you don’t want to be in the photo, keep moving and step away from the frame as you finish. If you want to stay in the image, all you have to do is stay still.
You can draw figures, trace objects, and even write words as long as the shutter is open. Just remember to write in reverse because the camera registers whatever you create backwards. It takes a bit of practice, but it doesn't take long to master. Light painting is all about trial and error, so just have fun doing it.
Long-exposure photography may be highly technical, but it’s also not an exact science. It’s the unpredictability that makes this type of photography fun. Despite all your calculations and adjustments, you still never know what you’re going to get. Feel free to play around with the settings and surprise yourself with the results.