 Until Linwood G. Dunn refined the design and use of the optical printer, effects shots were accomplished as in-camera effects.Dunn demonstrating that it could be used to combine images in novel ways and create new illusions.One early showcase for Dunn was Orson Welles' "Citizen Kane", where such locations as Xanadu (and some of Gregg Toland's famous 'deep focus' shots) were essentially created by Dunn's optical printer.