Their novel arrangement of four standard, off-the-shelf lenses keeps an object hidden (and the background undisturbed) as the viewer moves up to several degrees away from the optimal viewing angle.

"This is the first device that we know of that can do three-dimensional, continuously multidirectional cloaking, which works for transmitting rays in the visible spectrum," said doctoral student Joseph Choi. Other researchers have already developed 3D acoustic cloaks and Stanford research into optical metamaterials may yield more versatile invisibility cloaking, while the light-scattering approach of active invisibility cloaks could be easily defeated in practice.