Macbeth is going to have his own unique char. The chair should be clearly fit for a king. This will make the confusion of the scene more intense when Lennox says “Here is a place reserved, sir.” Macbeth will clearly have a place to sit, or it appears that way to the guests. The camera should sweep past the chair to show the empty char and confused looks of the lords. When it sweeps back Banquo’s ghost wll be in the place.