Self-organization of nano-size spherical particles in opal-like structures has been demonstrated to be a powerful mean to build three-dimensional (3D) photonic crystal. We here present a simplified sedimentation process leading to photonic crystal layer with a non-absolute bandgap in the visible range. The stacking organization is cross checked directly by classical optical microscopy (COM), atomic force microscopy (AFM) and scanning electron microscopy (SEM), giving a detailed scheme of the short range and long range organization, and indirectly by reflection/transmission spectroscopy for different incidence angles. The results show a very good resonance associated with a low cost deposition technique. The implementation of our method for further application like photonic waveguides is also discussed.