The first accessory I purchased when I worked as a sports photographer some time ago was a motor drive for my Nikon SLR. It enabled me to snap off a series of shots in rapid succession, which came in very handy when a fullback broke through the line and headed for the end zone. Even a seasoned action photographer can miss the decisive instant when a crucial block is made, or a baseball superstar's bat shatters and pieces of cork fly out. Sequence-shooting simplifies taking a series of pictures, either to ensure that one has more or less the exact moment you want to capture or to capture a sequence that is interesting as a collection of successive images.
Digital cameras provide "motor drive" capabilities that are, in some ways, better than what you get with film cameras. For one thing, a motor-driven film camera can eat up film at an incredible pace, which is why many of the high-end professional models are used with cassettes that hold hundreds of feet of film stock. At 3 frames per second, a short burst of a few seconds can burn up as much as half of an ordinary 36 exposure roll of film. Digital cameras, in contrast, have reusable film, so if you waste a few dozen shots on non-decisive moments you can erase them and shoot more.
The increased capacity of digital film cards gives you a generous number of frames to work with. A 5-megapixel camera that I sometimes use for sports photography can record almost 100 frames in the default Fine mode (in this case a JPEG file) on a single 256MB CompactFlash card. Even at three or four frames per second for short bursts, I can take quite a few pictures before it's time to change cards.
One drawback to shooting sequences with some digital cameras is that the number of frames you can take in a row might be limited by the amount of buffer memory in your camera and the speed with which the camera can write the images to the memory card. You might be able to snap off five or six pictures, then be forced to wait a second or two before you can take more photos. That limitation can be frustrating when you realize your first burst of images didn't capture the most important action and you watch the fullback scampering past you while you stare helplessly at the flashing red light on your camera that indicates your previous photos are still being written to the memory card.
Even so, a digital camera with any sequencing capabilities at all can come in very handy, as I discovered recently at an amusement park. I was having trouble capturing my kids as they zoomed by on a chair swing ride. I set the camera on its multiple-shot mode, and then pressed the shutter release when they came into view, snapping off several pictures like those shown in Figure 3.18. It still took me several tries to get the photos I wanted, because even at three frames per second many of the pictures captured "in-between" moments when one or more kids were partially in or out of the frame.
Digital cameras provide "motor drive" capabilities that are, in some ways, better than what you get with film cameras. For one thing, a motor-driven film camera can eat up film at an incredible pace, which is why many of the high-end professional models are used with cassettes that hold hundreds of feet of film stock. At 3 frames per second, a short burst of a few seconds can burn up as much as half of an ordinary 36 exposure roll of film. Digital cameras, in contrast, have reusable film, so if you waste a few dozen shots on non-decisive moments you can erase them and shoot more.
The increased capacity of digital film cards gives you a generous number of frames to work with. A 5-megapixel camera that I sometimes use for sports photography can record almost 100 frames in the default Fine mode (in this case a JPEG file) on a single 256MB CompactFlash card. Even at three or four frames per second for short bursts, I can take quite a few pictures before it's time to change cards.
One drawback to shooting sequences with some digital cameras is that the number of frames you can take in a row might be limited by the amount of buffer memory in your camera and the speed with which the camera can write the images to the memory card. You might be able to snap off five or six pictures, then be forced to wait a second or two before you can take more photos. That limitation can be frustrating when you realize your first burst of images didn't capture the most important action and you watch the fullback scampering past you while you stare helplessly at the flashing red light on your camera that indicates your previous photos are still being written to the memory card.
Even so, a digital camera with any sequencing capabilities at all can come in very handy, as I discovered recently at an amusement park. I was having trouble capturing my kids as they zoomed by on a chair swing ride. I set the camera on its multiple-shot mode, and then pressed the shutter release when they came into view, snapping off several pictures like those shown in Figure 3.18. It still took me several tries to get the photos I wanted, because even at three frames per second many of the pictures captured "in-between" moments when one or more kids were partially in or out of the frame.
Figure 3.18. You might need to take several sequences to capture the exact photos you want.
Many models have several different sequence or continuous advance modes. Here's a list of the most common options:
- Single frame advance. This is the default mode of most digital cameras. A single picture is taken each time the shutter release is pressed. With less expensive cameras that have little buffer memory built in, you might actually have to wait until the picture is stored on the memory card before you can snap off another one. Fortunately, most cameras, especially digital SLRs, are fast enough to let you take one picture after another almost as quickly as you can press the button.
- Continuous advance. In this mode, if you press and hold the shutter release button, the camera will take pictures in sequence for as long as the button is held (within limits). The number of pictures taken per second, and the number of photos you can take in one burst are limited by the buffer memory of your camera, which in turn is filled up more quickly at higher resolutions and lower compression rates. Whether you're using automatic or manual focus can also affect your speed of capture. In general, using manual focus and lower resolutions will let you capture more pictures, more quickly. Continuous advance might allow grabbing photos at 2 to 3 pictures per second, with a limit of around 7 to 20 photos before you must stop and wait for the burst to be stored on the memory card. One camera I use will let you capture 42 lower-resolution pictures in a row at 1280 x 960 resolution, or 84 really low resolution pictures in a row at 640 x 480.
- High-speed continuous. This mode is similar to continuous advance, but at a higher frame rate, perhaps 3 to 4 frames per second, with the same kinds of limitations on the number of pictures in a single burst. Figure 3.19 shows a short burst shot in this mode.
Figure 3.19. Short bursts can capture action sequences.
- Ultra high-speed continuous. In this mode, the camera sacrifices resolution for more frames per second. One of my 5-megapixel cameras drops down to producing 1.3-megapixel images in ultra high-speed mode, but can crank off a half dozen frames per second. If you're analyzing your golf swing, or want to capture images at a high rate of speed, 1280 x 960 pixels should be plenty.
- Motion picture. Many non-SLR digital cameras offer a "movie" mode that grabs 30 seconds or more of motion (and audio) and stores all the frames as a video file on your memory card. The resolution might be only 640 x 480 pixels, but this mode is a handy way of capturing some film clips.
- Time-lapse/interval. This mode lets the camera take pictures at intervals you specify, creating either a series of still images, say, of the setting sun, or a timelapse movie of a flower opening. For best results, your camera should be locked down on a tripod, and, if the sequence will be a long one, powered by an AC adapter.
- Bracketing. This mode also captures a sequence of pictures, but the intent is not to freeze moments in time but, instead, to grab a series of pictures (usually three) at several different settings: a default setting and a pair that adds or subtracts a little from the parameter being bracketed. For example, if you choose exposure bracketing, the camera will grab one photo at the metered exposure, plus one that gives more exposure and one that gives less exposure. You can set the bracket increment (for example, +/– 0.5 EV or +/– 1.0 EV) before you shoot. If your camera is versatile, you might be able to switch to shutter priority mode to activate bracketing using shutter speeds only, or to aperture priority mode to bracket using apertures only.
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