The smaller your camera, the more susceptible it is to even the slightest tremble, which can leave your photos looking like Impressionist paintings. Fortunately, optical image stabilization has trickled down from pro cams to the shake-prone pocket models. The cameras use motion sensors to detect any quiver and move a piece of the lens to compensate for it. I tested three in the most blur-inducing scenarios: in low light without a flash-the slow shutter speed gives you more time to twitch-and at full zoom, which magnifies shake.