A method for selecting one from among a plurality of three-dimensional (3D) cameras comprising calculating, in a computer, a plurality of z-space
cut zone flag values corresponding to the plurality of 3D cameras, then comparing the z-space
cut zone flag corresponding to a
reference monitor image to a plurality of candidate z-space
cut zone flags corresponding to candidate monitor images. In response to the results of the calculations and comparisons, a safe / not-safe indication is prepared for displaying on any of a variety of visual displays, at least one aspect of the safe / not-safe indication, the at least one aspect determined in response to said comparing. The method uses 3D
camera image data, 3D camera positional data and 3D camera stage data (e.g. interaxial data, convergence data, lens data) for encoding the 3D camera data into an encoded data frame which is then transmitted to a processor for producing a visual safe / not-safe indication.