Ghost of Banquo Scene

I found this banquet scene directed by Philip Casson more effective than Polanski's one. In class we mostly agreed that from the beginning of the play, audience knew more about Macbeth's reality and inner thoughts more than the characters in the play. Therefore, in the banquet scene it is better Banquo's ghost to be seen by audience in order to be involved in his experience. However, as soon as I watched Casson's banquet scene, which the ghost is invisible, I find it more effective than Polanski's. I think when the ghost is invisible we are more likely to focus on Macbeth's reactions to understand what's happening and see clearly his anxiety, fear, panic and mood swings. Also Ian McKellen (aka. Gandalf) in Casson's Macbeth reflects Macbeth's conflicts more realistic than Polonski's.