Video see-through design for merging of real and virtual environments

A head mounted display (HMD) that is optically opaque with respect to the outer world can be provided with see-through capability by mounting video cameras to the outside of the helmet. Stereoscopic views of the physical space surrounding the wearer are captured by the video cameras, and are projected to the display screens inside the HMD. The conditions necessary for mounting the cameras to a pre-existing, non-see-through HMD are described, and the advantages and disadvantages of different mounting schemes are discussed, together with the design of the video cameras lenses to be used with this specific application.<<ETX>>