Synchronisation of operations in a scanning microscope

To improve images, a scanning microscope is operated to scan an area of a luminescent specimen, controlling the excitation light or image capture device so that light emitted from the specimen is only incident on the image capture device sensor for a specific time period equal to that required for scanning the whole of the area of interest n times, where n is a whole number equal to or greater than 1. The scanning system is a confocal system, in which excitation light passes to the specimen via the scanning system and light emitted by the specimen passes in another direction via the scanning system to an image capture device, for example a CCD camera. In one example the system comprises a Nipkow disc scanner in which the pattern of openings in the disc is such that rotation through A degrees results in scanning the whole area of interest and the specific time period corresponds to nA degrees of disc rotation.