1. A display system comprising: an array of cameras arranged with angularly-spaced orientations to cover a wide field of view; a plurality of display generators associated respectively with said cameras, each generator being operable to display an individual image representing a respective part of the field of view, the arrangement of the cameras and the generators being such that the individual images each correspond to a part of the field of view which overlaps with at least one adjacent part of the field of view; and an optical system associated with the display generators for viewing the said images simultaneously in an overlapping arrangement to provide a continuous composite image of said wide field of view; the display system further comprising electronic control means operable to predistort said individual images corresponding to adjacent parts of the field of view, whereby an observer viewing the composite image is substantially unable to discern any mismatch between the individual images representing adjacent parts of the field of view, even with some head movement.