Lighting High-Speed Action
| 26 August 2010
Action photography has always had it's challenges. Anticipating where and when the action will happen, being in the right spot for the best angle, composing the shot by having your subject in the right area of the image at the right time, making sure the focus is where it should be, balancing shutter speed with panning/tracking techniques to freeze the action or convey the speed with motion blur, timing the shutter in order to capture the action at precisely the right moment... all these things converge in a fraction of a second, making action photography a difficult skill that is acquired and refined over years of practice.
There are many tools a photographer uses to make the task of action photography possible or easier... cameras with minimal shutter lag, fast autofocus, high shutter speeds, and fast frame rates; fast lenses that allow the camera to autofocus quicker especially in low light situations, zoom lenses to get them closer to the action when physical proximity is impossible or impractical, etc. Recent advances in technology have helped tremendously in giving talented photographers better tools to work their magic with, but the one I'd like to talk about today is lighting. One variable that is difficult to control in large spaces where a lot of action happens (ie: outdoors, large sporting arenas, concert halls, etc.) is the amount, direction, color and quality of the light. As a photographer, many times you are at the mercy of the weather or the existing lighting at the facility (which is usually dim and has a dramatic color cast).
Controlled Lighting: As a professional photographer, I do a lot of controlled lighting photography—everything from product shots in a studio to on-location lifestyle shots—where high powered strobes and light modifiers are used to create perfectly lit images, sometimes with dramatic lighting that shapes the message the image will ultimately convey. So I have developed a self-imposed expectation that we produce images that are technically clean and perfectly lit as possible. I think that over the years of receiving that kind of images from us, the standards of our clients are starting to rise as well. So naturally I have a tendency to visualize action shots lit with that same kind of controlled lighting—it's hard for me to allow my standards to slip and accept images with mediocre lighting or excessive amounts of noise or artifacting for example.
Sync Speed: But there are many huge challenges to combining action photography techniques with controlled studio light equipment and techniques. Some of the more obvious examples include the logistics of transporting lots of equipment to a mountainside, or the practicalities of having all that gear on a live race track or event stage or the power required to light the subject from far away so the lighting equipment is out of the way, and powering that equipment where high capacity electrical outlets are not available, just to mention a few. But the bigger challenge, and one that most people are unaware of is because of how current camera shutters work, almost all modern cameras still have the limitation of a maximum sync speed of around 1/200 of a second. That is not nearly fast enough to capture most action and freeze it. In most cases, you'd need to be at least 1/1,000 of a second or faster to minimize or eliminate motion blur.
Flash Duration: Studio lights typically have a very short flash duration in the thousandths of a second range which means that as long as there is no ambient light reaching the camera sensor, a quick pulse of light any time during that 1/200 of a second when the shutter is open will register as if the shutter had only been open for that flash duration, effectively freezing the action. That is why you will see night-time ski photos for example (or photos shot in a studio) that are obviously lit and incredibly sharp. But when it comes to combining ambient light with strobe lighting to freeze the action, there are additional challenges. You can combine slow shutter speeds of say 1/30 of a second (or even a full second) to create motion blur and then pop the strobe right at the end of the exposure to paint the subject over the motion blur, but freezing the action and the ambient light on the surroundings is a big challenge.
High-Speed Sync: Some small speedlights have the ability to pulse a very fast series of smaller flashes so that as the shutter curtain moves over the camera sensor at speeds above the maximum sync speed, each strip of the sensor is hit with light from the strobe, essentially making one contiguous image that appears to have synced the flash output at a high shutter speed. That is great, but because of the small amount of light they can output (approximately one tenth the amount of most studio lights), and how quickly light falls of over a given distance (if you double the distance to your subject, the amount of light that reaches the subject is one fourth as much), a single speedlight is effectively useless in many action scenarios. Even in the few situations where a speedlight could be effective (ie: a smaller object in close proximity to the flash), the amount of depth of field available is severely limited. That means that everything may not be tack sharp because the focal plane is so narrow that even though the action may be frozen in time, much of it may not be in focus. So even under the best circumstances, a speedlight is not the perfect solution.
Of course, at Avid Creative we always want to push the boundaries and get past the technical limitations to create the best, most stunning images possible, so we've developed a solution to allow us to capture high-speed action with ambient light and controlled strobe lighting to produce some spectacular action photography. We are still in the testing phases of this new way of lighting high-speed action, but initial tests look very good. Watch for more controlled lighting action images from Avid Creative in the coming months. And if you have a project that could benefit from our new abilities, please let us know.
