This film brings to light the line between privacy and awareness, and how these two things work in partnership with one another while also being opposites. These two things are represented through the technique of lighting. For one, the film often shows characters that are suddenly “enlightened” – whether it be to ideas or information– by depicting them in key light. Oftentimes, their surrounding environment is dark to emphasize this enlightenment. On the other hand, it shows characters who are “In the dark”– or in a state of unknown and mystery– depicted in darkness. An example of this is in 48:56-50:00. In the beginning of this scene, Lisa doesn’t believe Jeff’s theories about Thorwald committing a crime. She’s depicted in low lighting while Jeff has overhead lighting directly on him. Then, as she sees Thorwald putting something in a suspicious box, she stands up and becomes enlightened to Jeff’s theories. While she is standing up, she is stepping into the overhead light that is above Jeff. There is visual evidence that she goes from being “In the dark” to becoming “enlightened”. This encourages readers to question what is means to be “enlightened”. At this point in the film, the viewer is still unaware of whether Thorwald committed the murder or not, but the change in visual lighting represents Lisa’s perspective opening up for more possibilities. This shows that for Lisa’s character, light represents awareness, and in turn can be translated to light representing safety and comfort. On the other hand, darkness – for Lisa’s character– represented the unknown.
This contrasts with how light represents different things for Jeff’s character. After being conditioned to being a watcher, Jeff feels safer in the dark. In 39:28-40:00, Jeff steps out of the light to prevent himself from being seen by suspecting neighbors. At this point, darkness does not represent the unknown for his character but rather represents feeling secure. He hides in the dark because darkness provides privacy. This idea contrasts with the characters of the neighborhood residents. When the other characters are in their homes at night, their windows are dark. This leaves them unaware of anything happening right outside of their homes. They don’t know anything about their neighbors and therefore are always “in the dark” about them. This idea is even emphasized when the neighborhood dog dies, and the owner blames it on the neighborhood’s lack of care for one another.
As a result, the viewer is made to question what it means to be aware. If darkness for one character is the unknown, but to another character is privacy, then what factors contribute to these differences in perspective? Through lighting, Hitchcock allows the viewer to feel either unsafe or safe depending on which characters are in certain lighting. He proves that the line between privacy and awareness is subjective. He shows the viewer the flaws of the two extremes: being unethically over aware and being completely unaware. He shows the extremes of this spectrum within Jeff’s character and the neighbors’ characters. Both sets of characters face their own internal issues that are only heightened by their opposing perspective of being aware.