Volume VI of the HSCA's Appendices is the report of the HSCA photographic panel. The photographic panel examined a much wider variety of photographs and films than did the Warren Commission. It reported on the number and timing of shots via blur (jiggle) analysis of the Zapruder film, and conducted a trajectory analysis as well. It conducted authenticity studies on the Oswald "backyard" photos and the Kennedy autopsy photos, although documents which came to light in the late 1990s cast doubt on the panel's work related to the autopsy photos (see ARRB staff memos). The panel reviewed photos of the "grassy knoll" in order to determine if a gunman was visible in them, and it also examined particular photos to try to settle questions relating to the identity of persons in the photos.