Many circumstances necessitate long exposures, but they’re most commonly reserved for low-light photography. Cityscapes at night, dawn and dusk landscapes, star trails, Milky Way captures, light painting, etc. all fit the bill. But, there are many more times when it’s necessary to enter the realm of multi-second exposures. Some are out of necessity. Others are used to make something creative. Regardless of their reason, long exposures dictate that photographers take caution for a number of technical reasons. Incorporate the following into your workflow if you delve into the world of multi-second photography.
A tripod is essential if you want sharp images. Along with it, I also recommend you use a cable release. Even with the camera on a tripod, the simple pressing of the shutter can introduce movement and degrade the quality of the photo. To further ensure sharp images, use mirror lock up. This is especially true if you use a long lens and shutter speeds between 1/2 and 1/60th of a second. If there’s wind, be patient and wait for a lull. If the composition includes leaves, flags or other things that move in the breeze, they’ll be soft. Wind can also impart motion to the tripod and camera. If you have a camera strap attached, wrap it around the body so it doesn’t act like a windsock. If the wind is strong, keep your tripod as low to the ground as the composition allows. The lower it is, the more stable. If you include people, have them hold still. Try to minimize their size but still make them a key component. The smaller in the frame they appear, the less motion they reveal.
Creative Motion: When applied strategically, if motion is introduced into an image, it can become artistic. Be sure the end result looks intentional rather than passing off an accident as “art.” Ironically, for two of my favorite techniques that show motion I still use a tripod. One is panning. I level the camera and tripod and then loosen the knob on my pan and tilt head that allows horizontal movement. While the action passes in front of me, I follow it and press the shutter as soon as the subject is perpendicular to the camera. The result is a sharp subject with an out-of-focus streaked background. Be sure to stop the lens down or lower the ISO to obtain a slow enough shutter speed to create the blurred background. Neutral density filters come in handy. The “proper” shutter speed will be determined by the speed at which your subject moves and how much blur you want to impart to the background.
The other technique also involves panning, but I use the vertical axis of my pan and tilt head. I try to work on overcast days so the light is low and soft. I set my ISO to the lowest my camera allows. When necessary, I attach a 3- or 6-stop neutral density filter to provide slower shutter speeds. Compositionally, I seek out strong vertical subjects. Buildings, trees, lampposts, etc., all work well. Ideally, I go for a two- to three-second exposure and slowly pan either up or down. The end result is streaked tones of the subjects. Move the camera slowly to reveal some reality of the subject.
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