The invention relates to a rapid prototyping apparatus for the manufacturing of three dimensional objects by additive treatment of cross sections comprising a wholly or partially light-sensitive material, said apparatus comprising at least one light source for illumination of a cross section of the light-sensitive material by at least one spatial light modulator of individually controllable light modulators, wherein at least one light source is optically coupled with a plurality of light guides arranged with respect to the spatial light modulator arrangement in such a manner that each light guide illuminates a sub-area of the cross section.According to the invention, it is possible to obtain a significant simplification of an RP design system, just as the apparatuses designed are essentially capable of creating prototypes of any size, according to the invention.