Seven examples of distortions that occur through a not entirely round lens, recto - printed, photomechanical print, page, photographs, photographically illustrated books, abc, a. Astigmatismus : Einstellung auf die eine Bildebene, S. 12., c., :, Andere, 12., b., zwischen den Bildebene, 12., de, d. Astigmatismus : the Vertikalen since unscharf, the Horizontalen scharf, S. 12., e., : the small Quadrate since verzerrt, S. 12., fgh, f. Aussere Coma. Image left, S. 14., h. Inner Coma., right, 14., g. Astigmatismus mit Coma, 14., Taf. IV., height 215 mm, width 138 mm, maker, manufacturer, 1890 - 1895, paper, collotype, photoprint