Tyler shoots action sports, like skiing and snowboarding. On a bright, sunny day he has absolutely no problem getting a fast-enough shutter speed at low ISOs to stop the fastest action in the camera. But what he can’t do at a low ISO is stop that fast action at a very narrow aperture—say ƒ/16 or ƒ/22. That’s where the high ISO comes in—providing him the ability to shoot at ISO 1000 as if it were 200, with a shutter speed of 1/1000 of a second and an aperture smaller than ƒ/16
What’s so great about ƒ/16 for action-sports photography? That’s what Tyler pointed out to me that came as such a pleasant surprise: It allows him to create starburst effects.
Of course! Why hadn’t I thought of it sooner? It’s neat enough to shoot a skier or snowboarder on a bright, sunny day, rim-lit with sunlight to set them off from the blue sky background. But add to that the ability to create a dramatic starburst effect simply by stopping down the aperture, and suddenly those action photos get a little more special.
Even if you don’t have the latest generation of low-noise/high-ISO cameras, you can put that knowledge to good use. At apertures smaller than ƒ/16, direct light from the sun or other pinpoint sources will create a starburst. (A cloudy day or softened light source just won’t cut it.) This applies to action photography, landscapes, portraits or any outdoor or studio-lit subject you can imagine. The key when attempting this technique with sunlight is to make sure your subject is providing some relief from overpowering lens flare. A bit of direct sun viewed through trees or inching its way out from behind a skier is enough to create a starburst without worrying that flare will overpower the whole scene.