The present invention relates to an optical system for reproducing and/or recording optically readable effects on an associated optical record carrier by means of a number of radiation sources. The number of radiation sources comprises a first radiation source capable of emitting a first radiation beam, and at least a second radiation source capable of emitting at least a second radiation beam. The system further comprises beam dividing means for separating at least the first beam into a first main beam and at least a first auxiliary beam, moreover the system comprises photodetection means capable of detecting reflected light from an associated optical record carrier, wherein the optical system is adapted to perform radial tracking from the reflected light of the at least first auxiliary beam being positioned in a first guard band comprised on the associated carrier, and wherein the number of radiation sources is less than or equal to the number of tracks.