Photo: Richard Walker via Flickr // CC BY 2.0
When I discovered the basics of shutter speed as a new photographer, long exposure photography fascinated me. Like most beginners, I found it fascinating to know how to intentionally create blur and smooth waterfalls into a white mass and make traffic turn into lines in the dark. Tripod, shutter priority mode, and tada! A long exposure.
But long exposure photography shouldn’t just stop at tripods, shutter speed, and waterfalls—and it doesn’t. You can bet photographers like Michael Kenna don’t just plop their camera on a tripod and choose a long shutter speed. These seven long exposure photography tips go beyond the basics to capture some truly stand-out images.
Photography tip #1: Use ND Filters For Daytime Long Exposures.
Most photographers discover long exposure photography as a technique to conquer dark landscapes—and it works well for that. But if you are only using the long exposure technique in the dark, you could be missing out on some amazing shots.
Daylight scenes can be just as opportunistic for long exposures—if you have the right gear. Neutral density filters will block out light so that you can use slow shutter speeds without overexposing the shot. Neutral density filters, along with the graduated version and polarizers, are among the three filters that are truly worth much more than the space they take up in my camera bag. The lighter filters, like ND2, don’t have a big effect, but if you use an ND 10 filter or higher, or even stack multiple square filters, you can create long exposures in broad daylight.
With a good set of ND filters, you’re no longer limited in when you can shoot long exposure images.
Photography tip #2: For great long exposure photography, go beyond the obvious subjects.
Sure, waterfalls make great long exposure subjects, but the best images have subjects that are a bit outside the norm.
Anything that moves in a predictable way can be a good subject for long exposure photography.
Clouds, the tide, or a light breeze across tall grass, for starters, work well for landscapes. Long exposure photography techniques can be used to photograph star trails, or any moving light sources like amusement park rides, fireworks, and traffic. Painting with light by using LEDs, sparklers or other light sources to create shapes in a long exposure is also a great way to get creative.
But slow shutter speeds can also go beyond blurring movement. Using an ND filter and a long exposure time can emphasize contrast, like where the sun peeks through the clouds—allowing you to leave everything but that shaft of light in near darkness. Using a long shutter speed can also emphasize reflections by smoothing out the water’s surface. Or, if you’re photographing a crowded scene, using a long exposure can actually eliminate the people (as long as they are moving).
Photography tip #3: Prevent light leaks by covering your camera.
Once you start experimenting with extremely long exposures that are several minutes long, you run the risk of introducing light leaks into the image. Light leaks will appear like globs of light on the edges of the image, or sometimes as a rainbow-like streak.
Light leaks are caused when the light comes into the camera where you don’t want it to. With a long exposure, light can come into the camera in some unexpected ways, like through your viewfinder. Many long exposure photographers actually cover their cameras to prevent light leaks—like putting gaffer’s tape over the viewfinder after they’ve composed the shot, cutting a hole in a black lens case and shooting with the case on, or putting a hat or jacket over the camera. Those solutions probably don’t look too pretty, but the images sure can without being ruined from light leaks.
Photography tip #4: Start with a shorter test shot.
The trouble with long exposure photography is that you have to wait awhile before actually seeing what your camera captured. I’ve wasted an evening or two trying to create a shot, only to find at the end that the settings weren’t right in the first place. If you want to see whether your settings produce an accurate exposure, you can take a test shot with a shorter shutter speed, but balanced out with a higher ISO.
Remember that each stop of light doubles or halves the amount of light.
So, if you adjust the ISO and shutter speed by the same number of stops, you can take a shorter test shot with the same exposure. You won’t be able to see how the motion will blur, but you can check your exposure quickly this way.
For example, say you want to take five-minute exposure at f/8 and ISO 100. If you instead shot at ISO 3200, that’s five stops difference (200, 400, 800, 1600, 3200) because you doubled the ISO five times. Most cameras adjust shutter speed in 1/3 of a stop, so you can click through 15 shutter speeds to get five stops of light; in this example, that’s ½. So, a ½ second, f/8 and ISO 3200 will get you the same exposure as a five minute, f/8 ISO 100 photo. If you’re like me and not so good with the numbers (or just want to make life simpler), you can download an exposure calculator app, like this one for iOS or this one for Android.
Using this method, you just checked that five-minute exposure in a half-second instead, so you didn’t have to wait five minutes before making adjustments to your exposure. This method won’t give you an idea of what the motion blur will look like, however.
While determining what shutter speed to use takes some experimentation, often a five minute exposure is good for a dream-like effect on clouds and waves, while longer exposures (15-30 minutes) are necessary for creating star trails and slower moving objects.
Photography tip #5: Stack your exposures for optimal image quality.
A list of photography tips wouldn’t be complete without exposure stacking. Long exposures have a tendency to introduce a lot of noise into an image, even when using a low ISO. Modern cameras with more megapixels can actually make the noise in a long exposure shot even worse, though some new cameras are designed to reduce the sensor overheating that causes long exposure noise in the first place.
Stacking the exposure, which is both a shooting and editing technique, is a good solution. Exposure stacking also allows for longer exposure times and using fewer ND filters.
Using this technique, you can also decide just how much motion blur you’d like after you’ve already taken the shots.
To shoot a stacked exposure, you’ll shoot just like you normally would for a long exposure (including a tripod and a remote release). Instead of taking one long exposure, you’ll divide the shot into multiple shorter exposures, like five one minute images instead of one five minute image. Once you stack the image together, you’ll get an effect that looks similar to total exposure time of all the images combined. If you’re unsure, take more than you think you need—you don’t have to use all of them later.
Once you have your shots, open up Photoshop and go to File > Scripts > Load Files Into Stacks, then select the files you want to combine. Make sure the two boxes at the bottom for “attempt to automatically align” and “create smart object” are checked, then click okay. Then, go to Layer > Smart Objects > Stack Mode > Mean. That “mean” mode creates an average of all the images, which creates a blur effect just like using a longer exposure. Once that’s complete, you’ll go through your normal post-processing routine.
Great long exposure photography requires much more than a tripod and simple understanding of shutter speed. Once you’ve mastered the basics, apply long exposure tips like exposure stacking and using ND filters and you’ll capture much more dramatic shots.
Post by Hillary K. Grigonis, a Michigan-based lifestyle photographer. When she’s not taking pictures, she’s writing (about taking pictures).