How-To: A Primer on Long Exposures
How-To: A Primer on Long Exposures
Text and Photos by Lynne Eodice
In contrast to using fast shutter speeds to freeze action, using long exposures is a very creative means to convey motion in a photograph. A blurred image can be a very impressionistic rendition of movement, giving the viewer a sense of sensation. This how-to story will cover blurred motion, panning, zooming your lens during an exposure and capturing streaks of light from traffic at night. Experiment with these simple techniques, and have fun getting dramatic images!
How much blurring you allow affects the quality of motion the photo conveys. In this image of a waterfall, I used a one-second exposure to make the water look very soft and silky. I was also in the shade, so I could use a longer exposure than had I been in bright sun. Also, the shutter speed you select will depend on how fast your subject is moving. A speeding car can blur at a faster shutter speed, say 1/60 second. In general, the slower the shutter speed, the more blur you’ll get. Speeds slower than 1/30 second will blur motion dramatically, but you’ll want to use a tripod to keep the rest of your photo in sharp focus.
When planning to shoot, keep in mind that the closer you are to your subjects, the more likely they will be to blur. The same is true of subjects moving across your field of vision rather than those approaching you head-on. The fastest-moving parts of a subject will be the most blurred.
A relatively sharp subject against a blurred background also conveys the feeling of speed. To achieve this effect, you must follow the subject with your camera during an exposure. As this example of a little girl on her scooter shows, panning focuses attention on the subject, while the background is de-emphasized. Panning is a tricky technique, takes practice, and the results are not always predictable. But it’s fun— and definitely worth the effort.
For best results, start tracking the subject from the moment it appears in your viewfinder. Stand firmly with the camera to your eye and rotate the upper part of your body in the direction your subject is moving. When you have the composition you want, release the shutter and continue following your subject in one smooth movement. Panning requires a somewhat slow shutter speed, but the exact speed will depend on the situation and your subject. I used shutter speeds of 1/15 to 1/30 second to photograph this subject.
Taillights & Traffic Streaks
By using a long exposure at night, your camera can record patterns of moving lights that can’t be seen by the human eye. Cars, trains, busses and other motor vehicles are excellent subjects for this technique. The vehicles often move too fast to be recorded on your camera’s sensor during a long exposure, yet their lights leave ribbons of bright colors across the scene. Busy roadways can become rivers of red and white.
It’s best to set up your tripod at locations where the ambient light (from streetlights and buildings) isn’t too strong, and where you can get a good view of fast-moving traffic. I like to shoot from a city sidewalk or on a bridge over a freeway at dusk. Your time exposures will probably be very long— from several seconds up to a minute— so a tripod is important. Use an ISO setting of 100 to 400, and although you’ll be using your camera on shutter priority, try to use very small apertures like f/16 or f/22 to prevent overexposure.
Zoomed Lens Technique
By adjusting the length of your zoom lens during an exposure, you can get some striking effects. The most common result of this technique, called zooming or racking your lens, is the appearance of strong lines radiating out from the center of interest. This can give your pictures a real sense of motion, even with an inanimate subject. Although you can shoot zoomed lens exposures during the daytime, this technique produces exciting patterns of lights at night.
To create a zoomed photo, you must use a slow shutter speed—no faster than 1/30 second and probably longer. I’ve used this technique with and without a tripod, but you’ll want to use one to ensure getting any additional camera movement during the long exposure. Zoom through the full range of focal lengths for maximum results, or zoom your lens just part way if you prefer—you’ll get interesting effects either way. You can zoom from the shortest focal length to the longest, or vice versa.
In a Nutshell:
• Use this technique for getting a blurred subject against a sharp background.
• Shutter speeds of 1/8 or slower will give you the most dramatic blur.
• Follow a subject with your camera during a somewhat long exposure.
• Use this technique to get a relatively sharp subject against a blurred background.
• Taillights and headlights on vehicles will be rendered as ribbons of light.
• Use a tripod and shutter speeds of several seconds to one minute.
• Zoom your lens during a fairly long exposure to get exciting effects.
• Use shutter speeds from at least 1/30 second, and probably longer.