I had a difficult time getting this shot, as these butterflies seemed to prefer having their wings up, rather than flattened out as they are here. But I was finally able to find one with its wings out, and was able to get into a good perpendicular position. Canon 100-400 at 400 mm, 20 mm extension, ISO 400, f/16, 1/200 second (manual mode), 550EX Flash EV +2/3, monopod with Arca-Swiss ballhead and Wimberley Sidekick.