Digital Photography: The Missing Manual

Minimizing Shutter Lag

Shutter lag is the time it takes for the camera to calculate the correct focus and exposure before it captures the scene. In many camera models under $700 or so, this interval amounts to an infuriating half-second to one-second delay between your shutter press and the moment the picture is captured. Trouble is, that’s more than enough time for you to miss the precise instant your daughter blows out the candles on her birthday cake, your son’s first step, and that adorable expression on your iguana’s face. In photography, fractions of a second are a lifetime (Figure 1-7).

Figure 1-7. “Did you get my head spin?” says the break dancer. “Did you get it? Tell me you got that shot! Tell me you got it.” Every digital photographer has a collection of these missed shots, thanks to shutter lag.

You can reduce or minimize shutter lag in a couple ways. First, you can set the camera’s focus and exposure manually, as you’ll learn in the next two chapters. That way, the camera has no thinking to do when you squeeze the shutter. Most people, though, eventually learn instead to prefocus. This trick involves squeezing the shutter button halfway, ahead of time, forcing the camera to do its calculations. To prefocus, simply keep your finger halfway down until the moment of truth. Then, when you finally press it down all the way, you get the shot you wanted with very little delay.

Unfortunately, neither of these techniques works in all situations. Manually focusing and prefocusing both take time and eliminate spontaneity. Until the electronics of digital cameras improve, the best you can do is to buy a model with the smallest shutter lag possible. Most brochures don’t mention shutter lag, so your best bet is to visit one of the camera-review Web sites mentioned in the box in Section 1.7. Many of them list the shutter-lag timings for popular cameras.