A focus tunable optical system includes a compound lens, which includes a plurality of focus tunable lenses. Further, the focus tunable optical system includes a controller, which is configured to shift a focus of the compound lens from a first focal plane to a second focal plane. To this end, the controller is configured to apply, individually to each focus tunable lens of the plurality of the focus tunable lenses, a control signal having a first value for the first focal plane and a second value for the second focal plane.