Improving the dynamic range that my digital cameras can capture is, for me, more important than getting higher resolution or more megapixels. A well-known technique for capturing more dynamic range is taking multiple captures of the same image using different exposures (i.e., bracketing). From these multiple exposures you then can create HDR (high dynamic range) images. I won’t explain HDR itself in more detail because it was covered recently (see “High Dynamic Range Photography,” by Dan Burkholder, PT, September/October 2007).
Unfortunately, the enemy of this technique is any sort of movement—whether of subject matter or camera. That is why exposure bracketing is usually only applied to static objects, and why the camera must be mounted on a sturdy tripod. Both conditions impose severe limitations. If these multiple exposures could be captured instantly, however, both issues would pose no problem. In the future, we actually may see cameras that can capture multiple exposures and still freeze fast- moving objects; for now, we may be getting close enough.
Recently, I received a Canon EOS-1D Mark III camera for review. This camera can capture up to 10 fps, and its target audience is sports and wildlife photographers. (I usually photograph more static nature or urban landscapes.) Once I got used to the 1D Mark III, I started experimenting with what I call high-speed HDR.* I set the camera to its highest burst rate and captured bracketed shots. That means a three-shot (-2, 0, +2EV) bracket sequence was shot in less than half a second. Why does it make a difference? Everything that does not move much in a half-second is frozen in all three exposures. It limits the camera movement and also captures all slow-moving objects reasonably sharply. I used this technique for at least 300 shots, and it started to change my photographic style.