After watching this particular scene I couldn't help but to be impressed. I feel that Polanski did an amazing job in showing the dagger floating there, and also showing that it was just Macbeth's imagination. By putting a faint aura around the knife, it showed that it was just his imagination and not real. Overall I feel that the film techniques were done quite well, especially for an older film.
The character development is always an important part of a movie. In Polanski's version of Macbeth, he did a good job of developing the characters from how we saw them at the beginning of the movie, to how they turned out in the end. For example at the beginning of the movie, we saw Macbeth dressed as a soldier. He also looked like a young clean cut man with no beard. These things gave him the characteristic of innocents. By looking at him in this state, you can't tell what he is about to become; a murderer that will pretty much do anything to become king. By the end of the movie, the character of Macbeth has had a drastic change, from a good man to a lost soul that eventually pays for his wrong doings. .
Lady Macbeth's character is unknown until she reads the letter from Macbeth. Then the camera shows her and we get a feeling for how she is. Lady Macbeth may look harmless but it is really her who pushes Macbeth into killing Duncan. As the movie progresses along, Lady Macbeth becomes more and more involved, to the point where she is pretty much forcing Macbeth against his freewill to commit the murders. She goes from a woman who wants her husband to become king, to a woman that comes up with a plan and helps Macbeth follow it in order to become king. It almost seems at one point that Lady Macbeth wants her husband to become king more than he wants to. Lady Macbeth's character changes quite a bit in the play mainly because she gets too involved in her husbands quest to become king.