Not wrong, blunted. RIGHT!! Masterfully so.
As blunted suggests, it is Toland who links John Ford (in THE LONG VOYAGE HOME, 1940 -- from Eugene O'Neil one act plays) to Welles (CITIZEN KANE, 1941). As expressed in these pages, Toland had experimented with deep focus since he worked with the German master, Karl Freund, on MAD LOVE (1935).
It was part of Welles' genius to gather this technique, and others, adding suggestions of his own, and apply them with such taste.
Directors since have incorporated deep focus into their bag of magic, although as Welles pointed out, it is harder to achieve in color film than in black and white. As in impressionistic painting, bright colors, where possible, are put in the foreground, dark shades to the back, to compensate.
A technique which Welles adopted, which may have been more original, was to place characters in the frame in relation to their emotional distance. Hence, in its most schematic form, the famous breakfast table marriage history of Kane and his first wife, Emily Norton Kane, using "swish pans" to show the growing gulf between them, as the years passed. Other examples abound.
He complemented the above techniques by raising and lowering sound volume, having diminished characters speak in lower, distanced tones than those in ascendancy or asserting themselves, etc., techniques he learned in Radio.