Method of exposing a substrate by a patterned radiation beam, comprising: —providing a radiation beam; —imparting the radiation beam by an array of individually controllable elements; —generating, from the radiation beam, a patterned radiation beam, by tilting the individually controllable elements between different positions about a tilting axis; —projecting the patterned radiation beam towards a substrate; —scanning a substrate across the patterned radiation beam in a scanning direction so as to expose the substrate to the patterned radiation beam, whereby the tilting axis of the individually controllable elements is substantially perpendicular to the scanning direction.