A method of determining the movement in position of the optical axis of a camera having an optical zoom lens, comprising the steps of: obtaining a test image at a predetermined level of optical zoom; applying a digital zoom to at least part of the test image, selecting a plurality of test points in the digitally zoomed test image; changing the level of optical zoom by a predetermined amount and changing the level of digital zoom; obtaining the test image at the different level of zoom; analyzing the digitally zoomed test image at the different level of optical zoom; searching at least part of the digitally zoomed test image at the different level of zoom for two of said plurality of said test points; converting the position of the test points in the digitally zoomed images into corresponding positions within the optically zoomed images; and determining the amount of movement of the optical axis on the basis of the difference in position between corresponding test points within the optically zoomed images.