In an optical measuring system for determining spatial position and orientation of objects, a plurality of measuring points on the object is registered by cameras, laser measuring devices or a combination thereof. For identifying the measuring points, one target of a specific intensity and/or size or a predetermined pattern (3) of a plurality of targets (4) having specific differing intensities and/or sizes is associated with each measuring point. The intensities and/or sizes of the targets are detected in a pixel image of the target (4) by summing up intensities sensed by pixels included in the image of the target. The targets are light emitting devices consuming differing amounts of energy, reflecting, black or white spots of differing diameter or spots of differing shades of gray or other suitable color.