According to Bill Krohn's "Hitchcock At Work", Bass' first claim to have directed the scene was in 1970, when he provided a magazine with 48 drawings used as storyboards as proof of his contribution. Krohn's analysis of the production, while refuting Bass' claims for directing the scene, notes that these storyboards did introduce key aspects of the final scene—most notably, the fact that the killer appears as a silhouette, and details such as the close-ups of the slashing knife, Leigh's desperate outstretched arm, the shower curtain being torn off its hooks, and the transition from the hole of the drainage pipe to Marion Crane's dead eyes. Krohn notes that this final transition is highly reminiscent of the iris titles that Bass created for "Vertigo". Krohn also notes that Hitchcock shot the scene with two cameras: one a BNC Mitchell, the other a handheld French "Éclair" camera which Orson Welles had used in "Touch of Evil" (1958). In order to create an ideal montage for the greatest emotional impact on the audience, Hitchcock shot a lot of footage of this scene which he trimmed down in the editing room. He even brought a Moviola on the set to gauge the footage required. The final sequence, which his editor George Tomasini worked on with Hitchcock's advice, however did not go far beyond the basic structural elements set up by Bass' storyboards.