Radiation from arbitrarily shaped objects in the vicinity of Kerr Black Holes

The properties of images of rings in Kerr geometry in each order are examined, showing that there are two principally different image types, depending on whether the extended emitting object has surface elements with larger declination relative to the equatorial plane than does the observer. In this case, the assumption of infinitesimal thinness of the emitting object as used for the general relativistic flux transformation until now, is an invalid approximation. Local images of a vertically extended accretion disc as seen by different observers are presented. They demonstrate the importance to take into account the first indirect image as well.