Patent attributes
A reflective tube centered on a lens of a camera is used in covert wide-angle photography in which and at least one reflected annular image is rotated by 180° to register it with the open-hole (zero-order) image to obtain a wide-angle corrected image. Any exposure differences in reflected images are balanced (or matched to the zero-order image) and rotation of odd-order image(s) is done by dedicated electronics of the camera or a later computer program to align such images with the zero-order image while the photograph is taken of an object using a tube which is no longer than approximately 1/100th the distance of the photographic subject. The reflective tube can be a transparent material (such as Plexiglas®) whose outer surface is painted black to block stray light which would otherwise be transmitted by walls of the tube and to absorb second-surface reflections from inside.
