Optical effects artist Dunn claimed that "up to 80 percent of some reels was optically printed." These shots were traditionally attributed to Toland for years. The optical printer improved some of the deep focus shots. One problem with the optical printer was that it sometimes created excessive graininess, such as the optical zoom out of the snow globe. Welles decided to superimpose snow falling to mask the graininess in these shots. Toland said that he disliked the results of the optical printer, but acknowledged that "RKO special effects expert Vernon Walker, ASC, and his staff handled their part of the production—a by no means inconsiderable assignment—with ability and fine understanding."