Wednesday, May 22, 2013
Exposure Solutions: Sharp Action
Top tips for getting great photos of moving subjects
|Arising early one morning in Maui, I came upon a spot where both big waves and surfers were now arriving. After traversing down a somewhat narrow path along a rather steep cliff, I found the perfect shooting spot.
Within the hour more than 20 surfers had accepted the challenge offered up by these thunderous and sometimes unforgiving waves. It became clear quite quickly that most of the talent pool that was out there in the beautiful blue Pacific this morning had been at this surfing thing for some time. There was a kind of fluid poetry to their every move, a rhythm that seldom struck the wrong chord.
With my camera and a 200-400mm Nikkor zoom mounted on a monopod and my ISO at 100, I set my shutter speed to 1/1000 second and adjusted the aperture until ƒ/5.6 indicated a correct exposure from the front-lit blue sky above the horizon.
Although I was only there for less than an hour, I managed to record a number of really exciting images, most of the credit going to these guys who it seemed could turn on a dime. With the action below me moving at such a frantic pace, I chose to switch my autofocus mode to AF-Servo Mode, which means that my Nikon will be continuously keeping my subject in focus as I track it inside my viewfinder.
There is, perhaps, nothing more satisfying than an image of action frozen in crisp, sharp detail, allowing us the time to scrutinize and analyze every nuance—down to the smallest speck. We can return again and again to savor that moment, frozen in time, long after that particular action has ceased. The challenge, of course, is freezing that action in the crispest detail while still maintaining a good overall exposure.
There are many keys to recording great action shots: lens choice, distance to the subject, direction of the subject (i.e., is it moving toward you, past you to the left or right, or up and down in front of you?) and ISO; but the most important key is shutter speed.
Many beginning photographers are surprised to learn that most outdoor sports-action shots can easily be recorded at shutter speeds of 1/250 to 1/1000 second. There's a widely held belief that much faster speeds—1/2000 to 1/4000—are needed for these subjects, but that's not true. During the late 1960s and most of the '70s, all cameras had a maximum shutter speed of 1/1000 second. Yet rarely did anyone hear a Sports Illustrated photographer complain that he missed a shot because 1/1000 second wasn't fast enough.
For many experienced shooters, getting to good exposures at 1/500 or 1/1000 second is the direct result of using the right ISO. Is it necessary to use a high ISO?
Those who prefer higher ISOs when shooting action argue that they make it easier to employ action-freezing shutter speeds, such as 1/500 or 1/1000 second. Also, with the higher ISOs you can use smaller lens openings, which offers greater depth of field. The greater your depth of field, the larger your area of sharp focus. A bigger area of sharp focus helps you maintain tack-sharp focus on your subjects as they move around.
The next consideration is the direction of the action. Is it coming toward you, is it moving side to side, or is it traveling up or down? When action is moving toward you or away from you, you can get away with using a shutter speed of 1/250 second or 1/500 second. When the action is moving side to side, or up and down, shutter speeds between 1/500 and 1/1000 are the norm.
Bryan Peterson is a professional photographer, instructor and author of several popular books, including Exposure Solutions: The Most Common Photography Problems and How to Solve Them (Amphoto Books). He's also the founder of the online photo school Perfect Picture School of Photography at www.ppsop.com.