A projection device comprising a MEMS mirror which oscillates about one or more oscillation axes to scan light from one or more lasers, across a display screen, to project pixels which define an image onto a display screen is disclosed. A method comprising selecting a laser class for the projection device; calculating relationship between maximum accessible emission limit and distance, for the selected laser class, for a predetermined number of black pixels in an image; determining the distance between a display screen and the projection device; and modifying a pixel stream which defines said image which is to be projected by the projection device, so that the pixel stream is provided with said predetermined number of black pixels is provided.