Monday, November 12, 2007
Trick Shots: Action
Stop fast action with these tips on everything from shutter speed to lenses
The Lens Connection
Action is often captured with telephoto lenses—after all, you can't simply walk onto a football field and start photographing the action while the game is going on. This requires faster shutter speeds, too, but introduces another angle-the speed of the lens.
Many compact, extended-range zooms can be difficult to use for action photography. They're too slow. That means that the largest lens opening on the lens, its maximum, is often rather small, typically ƒ/5.6 or even ƒ/6.3. You'll see pro photographers shooting with lenses that have ƒ/4 or even ƒ/2.8 as the maximum.
For example, on a cloudy day, you might get only 1⁄500 sec. at ƒ/5.6 (1⁄320 sec. at ƒ/6.3)—too slow to freeze soccer action, for example. With an ƒ/4 lens, this goes to 1⁄1000 sec., and at ƒ/2.8, 1⁄2000 sec. Fast lenses can be big and expensive, but if you plan on doing a lot of action photography, you should pay attention to the maximum ƒ-stops on your lens.
One way around this is to shoot with higher ISO settings. The newest digital SLRs offer amazing image quality at high ISO settings. The noise level is much reduced from the past and will give better results than what high-speed film used to offer.
The Fast Memory Card
Memory cards have gotten very fast, 80x, 100x and more. It might seem like you should use such cards to capture better action shots, but there's more to it than that.
The speed of a card affects how fast images are taken out of the camera's buffer, but has no effect on the speed of the camera itself. A camera will continuously take pictures at whatever speed it's capable of, then put those image files into the camera's memory (the buffer) until it's full.
At the same time, the camera is moving the files from the buffer to the memory card. How fast it can do this depends on the camera's capabilities and the speed of the card. A fast card will empty the buffer faster, meaning you can shoot more photos before it's full, but this happens only if the camera supports the speed of the card.
If you want to shoot faster (more frames per second), you need a camera that can do that. If you want to shoot more photos before the buffer is full (and the camera will stop shooting until it has free space), then a faster memory card may help.
For more tips and techniques, check out Rob Sheppard's latest book, Kodak Guide to Digital Photography, or visit his website at www.robsheppardphoto.com.
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