An optical system comprising a first optical unit and a first sensor unit for sensing electromagnetic radiation. The optical system also comprises a micromirror matrix unit which is arranged in the beam path between the first optical unit and the first sensor unit. The micromirror matrix unit is arranged to be able to be set in at least a first and a second state. In the first state, the micromirror matrix unit reflects incident electromagnetic radiation such that it reaches the first sensor unit. In the second state, the micromirror matrix unit reflects incident electromagnetic radiation such that it does not reach the first sensor unit. The invention also concerns a target-seeking system comprising such an optical system.