Sports Photography Quiz: Test Your Knowledge

At 1/1000 second, running players, swinging limbs and most balls move too little during the exposure to blur. At 1/60 or 1/30 second they smear. Very fast action, such as a tennis serve or a bird's wings, can need even faster speeds.

Continuous AF (often labeled AF-C) keeps adjusting focus as long as the focus button is held, following a subject that moves toward or away from the camera. Single AF locks focus once and holds it, so a moving subject drifts out of focus.

Panning means following a moving subject with the camera during a slower exposure, often around 1/30 to 1/60 second. Because the camera moves with the subject, it stays fairly sharp while the background streaks into blur that shows speed. Zooming during the exposure is a different technique, the zoom burst.

A 70-200mm f/2.8 has the reach for most sideline sports and keeps f/2.8 through the whole zoom range. That allows fast shutter speeds under arena lights and blurs the background to separate the athlete. Wider zooms such as 24-70mm cannot reach far enough from the sideline.

A wide aperture lets in more light, which allows the fast shutter speeds that freeze action without pushing ISO as high, especially indoors or under stadium lights. It also gives a shallow depth of field that blurs the crowd so the athlete stands out. It reduces depth of field rather than increasing it.

A monopod carries the weight of a long, heavy lens and steadies it, yet sets up instantly and lets you pivot to follow play. A tripod takes up space on the sideline and is slow to move, which is why many venues restrict them.

Sports events produce enormous volumes of images, most of which record sub-optimal moments between decisive actions. A keep rate of five to ten percent reflects the reality that capturing peak action reliably requires many frames, and that most captures are useful only as context for the best ones.

Motion blur from a shutter speed that is too slow ruins more sports frames than any other setting. Athletes and balls move fast, so speeds below about 1/500 second often leave limbs blurred. Raising ISO to keep the shutter fast is usually the better trade, since some noise is easier to accept than blur.

Reviewing images on the LCD during play requires lowering the camera from shooting position and directing attention away from the field. In fast-moving sports this creates a gap in coverage during which decisive moments can occur and be missed.

Back button focus moves autofocus from the shutter button to a button on the back of the camera. With continuous AF set, holding that button tracks the subject and releasing it holds focus, while the shutter button only takes the picture. That lets you switch between tracking and locked focus instantly as play changes.