Regardless of how firmly you hold your camera, with long shutter speeds, your photos will never be 100 percent sharp and will instead look blurred. The image stabiliser is one remedy to this problem. However, it is important to know how the image stabilisation mechanism functions to be able to counter shaky hands.
Digital image stabilisation uses the image processor to reduce blur. Optical image stabilisation is more effective, thereby allowing you to get steady shots at shutter speeds as low as 1/10 sec. While purchasing a digital camera or a telephoto lens, you should give preference to models armed with optical image stabilization.