Which mode?

Some cameras and lenses offer different IS modes. With Canon lenses, for example, Mode 1 enables the full range of compensation movement whereas Mode 2 is designed for use when panning to follow a moving subject. It switches off the IS correction for the panning direction and only corrects movement that is perpendicular to the panning. It’s also often possible to specify whether the stabilisation system is active all the time or just at the moment that the shutter release is pressed to capture an image. Keeping it active means that you see a steadier image in the viewfinder, but limiting it to activating at the point of capture increases the degree of correction available during the exposure, which can mean the image is sharper.