In a method and projection device to mark a surface of a three-dimensional examination subject, relief data (RD) of the surface are acquired and are used to establish a measurement information marking. A reference position value is determined, which represents a position of a radiation device of the projection device relative to the surface. A calculation of pre-distortion of the established measurement information is calculated in a processor marking depending on the relief data and the reference position value. A visually perceptible pre-distorted measurement information marking is radiated from the radiation device in the direction of the surface.
