People often associate long exposures with night photography. What is overlooked are the amazing photos you can get with longer shutter speeds, ranging from 1/15 of a second up to many hours. What’s more, these aren’t tricky, and don’t require sophisticated cameras and lenses. Because of the techniques associated with shooting at varying lengths of shutter speeds, I break them down into three categories: Shorter exposures, which go from about 1/20th of a second to several seconds, medium exposures, which go up to about a minute, and long exposures, which can be indefinitely long.
Shorter Length Exposures
“Shorter” versions of extended exposures are those where you typically want to capture motion blur of an object or action. You may either be shooting from a moving object, or you may be in a stationary position taking a picture of a moving object. What each of these cases have in common is the fact that they take place during the day. This means you have a lot of light available, and when there’s a lot of light, your camera’s shutter speed tends to be pretty fast. One way to slow down the shutter speed while maintaining the overall exposure balance is to use a very small aperture, also called “stopping down.” The smaller the hole, the less the light, the longer the shutter speed to get the light.
Technically, this isn’t rocket science. The challenge is the composition. Because things are in motion, it’s hard to frame your picture in real-time conditions that change so quickly, and deciding when to release the shutter. Expect to shoot many pictures of the same thing, hoping that one great shot will appear. One hint about composition is to pay attention to the direction of motion, since that will be the theme of the picture. Straight lines, curved motion, forward, backward. It’s all about leading the viewer’s eye from a starting point to an endpoint. It may be subtly implied, or very direct, but it’s the motion itself that you want to convey.
When shooting from a stationery position, something else in the scene must also be stationary, or the effect is lost. Hence, it is necessary to keep the lens stable during the exposure to keep those stationary objects still. For 1/8 of a second or so, one “can”, with enough practice, learn to be relatively still, but even then, it still requires repeated shooting. If you’re on a train, for example, you can use a tripod.
Moving clouds are also excellent subjects for extended exposures. For example, this photo of Mount Veronica, Peru, shows how clouds appear when they move over mountains. Shooting just about any night scene with moving clouds can produce interesting effects, but be careful not to expose for too long. Given enough time, the whites of the clouds will eventually pass by all the open spaces in the sky (even if it’s never entirely overcast), losing the “swoosh” effect.
Medium Length Exposures
Medium length exposures include those up to a minute or so, and are therefore the most common type of long-exposure work. The only thing required is a tripod or other sturdy object. Dusk, dawn and many nite scenes in cities (or traffic) are excellent candidates for these types images, because there is ambient light to fill in the shadows, which balance out the highlights.
As these photos illustrate, streaking lights from cars show a sense of motion, and are immediately appealing. The longer the exposure, the longer the car headlights streak. There are many ways you can play with this effect, and as you get more familiar with the process, you can experiment with the timing; when you start and stop such exposures has a great impact on the final result.
For example, consider the pair of images of the stopped bus. Both were exposed the same amount of time: 30 seconds. However, the headlights for the bus on right-hand image appear to “beam” forward. This is because the bus was stationary for the first 25 seconds before it began to move in the last five seconds. The brightness of the headlights were captured, but the bus’ movement isn’t captured because it doesn’t emit enough light itself (other than its headlights) to affect the longer-term imprint that already took place. A shorter exposure might not have provided enough time to imprint the stationary bus, and would have also allowed the brief time it was moving to have a more pronounced imprint. To successfully capture this effect, experimentation is critical. (It took about an hour to experiment with this—mostly involving having to wait for another bus to come by.)
A favorite subject among amateurs is fireworks. While beautiful, they can be highly unpredictable, so again, prepare to shoot many frames with more bad pictures than good ones. The main problem is figuring out what exposure to use. If it’s too long, the fireworks themselves overexpose, and if it’s too short, all you get is fireworks, and no background. The only solution to this is shoot for the background—that is, expose as if it’s a nite shot—and try to time your shutter releases so that the fireworks are either at the beginning, or the very end of the exposure. You’ll have to shoot at least one picture of the scene without any fireworks, just to
gauge what your base-line “nite” exposure is. Once you have that, you can time the fireworks accordingly. This way, the basic scene will come out right, and the amount of light from the burst won’t be over-exposed. You want at least a second of it to get the “motion” of the sparks, or the photo probably won’t come out pleasing. Again, experiment to taste.
Clearly, it’s a lottery game to determine when the operator is going to let off the next one, and it’s not even worth shooting when he lets them off back to back. Except for those situations, I’ll shoot every moment of a one hour fireworks display and be lucky if I come up with five good shots. And if there’s a strong wind, forget it. Similarly, the smoke can become a visual eyesore if there isn’t enough circulation to cycle it out during the performance.
I always try to compose fireworks to have some sort of foreground. As you know, fireworks involve bursts, flashes, and streaks, which are all over the map for making good exposures. Getting an “even” look involves timing. And that is governed by your noticing how the fireworks are spaced apart from one another.
Shooting During the Day
The challenge for obtaining long exposures in the daytime is how to reduce the amount of bright daylight to allow for a longer exposure. Stopping down your aperture won’t be enough for these, because you need to block even more light. The solution is to use a neutral density filter. These filters are tinted with a “neutral” color, serving no other purpose than to reduce the total amount of light into the camera. ND Filters come in many configurations, from one stop of light, up to thirteen stops, where each “stop” doubles the amount of time of your exposure because it blocks twice as much light as the previous stop. So, a picture that would normally taken at f16 @ 1/30 second can turn into a 30-second exposure with a 10-stop ND filter. People have been known to photograph the sun traveling across the sky all day using two 13-stop ND filters stacked on top of each other.
I usually carry with me a 5-stop and a 10-stop ND filter. And that’s where the fun begins for things like waterfalls or fog, to name two examples. Fog is rarely motionless, so it is often a great subject for extended exposures because its movement often appears as “flowing cream” when low to the ground. (You tend not to get this effect if the fog is hovering; this type of photo is best shot when you’re away from the fog.)
Flowing water has a similar effect as fog, and it’s much easier to find. Whether a river, or crashing waves, any type of liquid movement is a good candidate for longer exposures.