A method, device and computer program are detailed for modulating write light. For a plurality of pixel locations of an electro-optic layer of an optical write valve and across each of a plurality of consecutive frames, a set of pixel data bits is modulated across a first and a second pulse width period of the frame. The first and second pulse width periods, and adjacent pulse periods of sequential frames, are separated from one another by a pulse-off period that is at least equal to a response time of the electro-optic layer during which no bits are modulated. Separately in each frame, write light is output from each of the plurality of pixel locations according to the modulated pixel data bits in the frame. In an embodiment, the set of pixel data bits are modulated by applying a voltage at a pixel location of the electro-optic layer in synchronism with illuminating a light source that illuminates that pixel location.