Image Stabilization lets you take longer exposures without a tripod. This mechanism is in Sony’s Alpha 900 and 850; other Alphas use another version.
Sony’s Alpha 900 was the first full-frame DSLR with in-camera image stabilization; the A850 followed suit in late 2009. Since full-framers are bigger and heavier than APS-C sensors, adding IS required a more powerful mechanism. The module illustrated here helps capture sharper pictures by sensing camera shake and shifting the sensor in both directions to compensate—while adding little to the size and weight of the camera.