The present invention relates to an optical system for performing radial tracking on an associated optical record carrier. The optical system contains at least one radiation-emitting device capable of emitting at least three beams: a first beam for reading and/or recording information, and at least a second beam and a third beam for tracking. The optical system is adapted for radial tracking of the first spot from a tracking error signal generated based on the high-frequency component of the central-aperture signal of the second and third beams. The tracking error signal may be generated based on a difference signal of a DC-level of the power of the high-frequency components of the central-aperture signal.