The problem of 3D panel display systems either (a) requiring special glasses to separate left and right viewing images, or (b) having auto-stereoscopic 3D with compromised fidelity, is solved by providing a projection three dimensional (3D) display system for providing glass-free, 3D display to a plurality of viewing volumetric pairs (VVAs) in space corresponding to a hypothetical plurality of viewers' eye aperture pairs, the projection 3D display system comprising: (a) a dual-image projector configured to project both a left viewing tri-color image and a right viewing tri-color image; and (b) means for (1) receiving a tri-color mixed input beam encompassing the left and right viewing tri-color images, (2) multiplying the tri-color mixed input beam into a plurality of tri-color mixed output beams, and (3) focusing the plurality of tri-color mixed beams for viewing at the VVAs.