The inventive titanium alloy comprises, expressed in mass %: aluminium 4. Two of the four first sub-pixels are arranged in a same column and share a symmetrical axis, and the two second sub-pixels and the two third sub-pixels are alternately arranged on either side of the symmetrical axis. The light shroud blocks this ambient light entering the system at angles which allow the light to interfere with the illumination system or camera. Axi-symmetric and linear-symmetric reflectors provide directionality for specific applications. A top plate of the second mold assembly is positioned in contact with the middle plate so as to close the second mold assembly.