Focusing of a monitoring camera (100) with day and night functionality comprises selecting a focusing day mode or a focusing night mode based on the camera being in day mode or night mode. In focusing day mode, an IR laser range meter (110) will measure a reference distance continuously, and in the focusing night mode the IR laser range meter will only measure reference distance in response to a focus trigger signal being activated, and during a predetermined time period. The focus distance of the camera is set based on the measured reference distance.