In vat polymerization printer, light is projected from a digital light processing (DLP) light source towards an opening in a tank containing photo-curable liquid resin. A mask is used to filter the light from the DLP light source, the mask having pixels configurable to be individually transparent or opaque to portions of the light from the DLP light source. In a build area of the tank, the filtered light is used to cure the photo-curable liquid resin so as to form a layer of a partially formed object. The operation of the DLP light source is synchronized with the operation of the mask, such that light from the DLP light source with high intensity is transmitted through the transparent pixels of mask and light from DLP light source with low intensity is blocked by the opaque pixels of mask. The mask may enhance the resolution of DLP light source.