A method for processing digital media is described. The modulator changes the apparent orientation of one retarder stack relative to the other so that, in a first switching state of the modulator the two retarder stacks cooperate in filtering the spectrum of input light, and in a second switching state the two retarder stacks complement each other, yielding a neutral transmission spectrum. A second reset piston is retracted after a predetermined delay time following retraction of the first reset piston, the predetermined delay time being sufficient to allow the second pilot chamber to become substantially pressurized.