The present invention concerns a charged-particle multi-beamlet system that comprises a source of charged particles (301); a first multi-aperture plate (320) having plural apertures disposed in a charged particle beam path of the system downstream of the source; a first multi-aperture selector plate (313) having plural apertures; a carrier (340), wherein the first multi-aperture selector plate is mounted on the carrier; and an actuator (350) configured to move the carrier such that the first multi-aperture selector plate is disposed in the charged particle beam path of the system downstream of the source in a first mode of operation of the system, and such that the first multi-aperture selector plate is disposed outside of the charged particle beam path in a second mode of operation of the system. The source, the first multi-aperture plate and the carrier of the system are arranged such that a first number of charged particle beamlets is generated at a position downstream of both the first multi-aperture plate and the first multi-aperture selector plate in the first mode of operation, and that a second number of charged particle beamlets is generated at the position in the second mode of operation, wherein the first number of beamlets differs from the second number of beamlets.