Full-Parallax Authentication

The demand for high-security document features has driven research into optical technologies capable of producing effects that are both visually striking and extremely difficult to counterfeit.

Sample with full parallax effect from different perspectives (adapted from ODDS 2025 presentation).

At the recent Optical & Digital Document Security™ (ODDS) 2025 conference in Warsaw, Mengli Liu of Zhongchao Special Security Technology (ZSST) presented a breakthrough in this field: a 3D lightfield imaging technology based on microlens arrays that achieves a true full-parallax optical effect.

The physics of parallax

At the core of the system lies the microlens array (MLA), a periodic optical structure composed of thousands of microscopic lenses.

Each lens collects light from a slightly different angle of the underlying micropattern array, and when viewed by the human eye, these perspectives recombine into a single threedimensional perception.