What is low-key lighting, and why do we use it? Watch the video:
Important: The meanings of high key and low key are different for photography and cinematography.
The Subject and Background
The subject and background can be exposed differently. Compared to your subject, the background can either be bright or dark or medium. Medium is slightly under and doesn’t draw attention to itself.
Most films fall in the medium category. When cinematographers keep the background slightly below the main subject, they are signaling that their lighting isn’t trying to make a dramatic statement. They’re trying to show things as they are. So realistic scenes tend to follow this system. This is neither high-key nor low-key, just normal.
When the background is equal to or brighter than the face, we call it high-key. Sitcoms and comedies are a great example. The blacks can still be rich and deep, but the shadows are mainly bright, so the mood is cheerful. The most extreme example of this is when a character is against a white background. The contrast ratio is lower as well.
What is low-key lighting?
When the background is a lot darker than the face, we call it low-key. Low-key is what you get in film noir, or dark moody scenes.
The cinematographer is trying to tell us the mood is somber, literally by taking away light. Naturally the most extreme example of this is when the character is against a black background.
Both high-key and low-key lighting are derived from nature. The sun and moon are both point sources. On a clear day or night, their light casts harsh shadows. The main difference is sunlight is so strong and overwhelming it’s like a tsunami in a bathtub, the light just washes and bounces around everything so you mostly see a high-key on a bright day.
Surprisingly, a full moon does the exact same thing. It too is a point source and the shadows are harsh. The intensity is a lot lower, and the main difference is actually our eyes. Our eyes are designed to work well with sunlight, which we see every day, and we use cones. Full moon nights are a lot fewer, and we are designed to rest at night, so we use rods in our eyes. This is why the shadows are a lot darker at night.
To know more about rods and cones, read Driving Miss Digital.
What about low contrast scenes, like the ones Tarkovsky is known for? The shadows are similar to the face, so is it high key or low key?
It is neither. It is just a low contrast scene.
What about the face? If the face is in silhouette is it a high key or low-key scene? It’s neither. It’s a silhouette.
What if both face and background is underexposed?
Is this high key or low key? It is low-key.
A dark background is always low key, regardless of how the face is exposed. The face can be overexposed, like an interrogation scene, or normally exposed, or underexposed, and they’re all low-key scenes. Remember:
High key or low key is decided by the background’s exposure.
What about night street scenes? Are they high key or low key or normal?
They’re low-key scenes, because the background is dark. However, because you’re shooting at night, there’s no need to tell anyone it’s a high key or low-key scene. We only use the terms high key and low key in relationship to film lighting. With night, a dark background is sort of a given.
Typically the background is lower by two or three stops, but that depends on the reflectivity of the background. The same light hitting a brown wall will have a different feel to a black curtain. So when you light for low light you have to consider what the camera sees, and not what your incident light meter is telling you.
So, in short:
Low-key lighting is when the background is a lot darker than the face, or dark enough where details are hard to make out. And, it is a term you mostly use in reference to lighting a scene.
When do we use low-key lighting?
We typically use low-key lighting to show moody shots. However, that isn’t etched in stone. Nothing in cinematography is.
Woody Allen and Tim Burton have made comedies in low key. On the other hand, Jaws is mainly normal to high key, but is a horror movie.
Both Marvel and DC are superhero movies. One is normal to high key, while the other is mostly low key. Is the Joker a greater threat than Thanos? No, but DC uses low key as a matter of style. The world Batman lives in is low key, moody, crime-filled, almost beyond redemption. The world the Marvel universe inhabits is more optimistic.
It’s the background that matters. However, it is important not to be formulaic. You want to help the audience really feel the mood. To do that, you must first feel it. That’s the takeaway.
The following essay on low-key lighting was written by Sergio Cavalieri and edited/modified by Sareesh Sudhakaran:
How to light a scene in low-key lighting
In order to understand low key lighting and how to use it, let’s take a look at some basic principals of lighting.
When we’re considering the amount of light in a scene, it is important to keep in mind that there are many different variables that can change how a certain scene looks within the final movie.
The chosen color scheme, the framing, the amount of contrast, and several other aspects can cause the amount of light in a scene to change. For that reason, the amount of light measured often varies dramatically.
Early in my career as a filmmaker, I would use a light meter most of the time to measure the amount of light in any scene. I always had a hard time with that method simply because of the fact that depending on what or who you are lighting, that subject or scene will reflect the same amount of light that you throw at it completely differently.
Pretty soon I began to realize that the problem is that a light meter measures the amount of light that you are “throwing” at something without considering the way that the light will bounce back and hit the sensor.
For instance, a subject with white skin will reflect light much differently than a person with darker skin. A scene shot in front of a white background (apple ads style) will look much different than a scene filmed in a room with predominantly dark colors.
I began to discover this, and after trying several approaches, I finally ended up with my favorite way to measure exposure: by using the false color on a monitor with a LUT.
I am not in any form criticizing the use of light meters. I am however affirming that I have found an easier and faster way to nail exposure by using false color, as it makes it possible to measure the reflected light and consequently the final result of how the lighting will look.
If the light meter measures the light you are “throwing” at something, the false color measures the way that light “bounces back” from that something.
I suggest that you try the false color approach in your own work and if it works for you great, if not, use your preferred method, as exposure can be measured in many different ways.
For the purpose of our investigation on what “Low Key Lighting” is all about, we are going to think about exposure (the amount of light on a final scene) in terms of percentage. Here is an example. Let’s consider that zero percent of the light is pure black. Given the light sensitivity of the sensor of your camera, (this can vary from camera to camera as different cameras are more sensitive to light than others) 100 % will be considered pure white.
In this situation, a scene that is closer to 0% is low-key, A scene that is closer to 100 is high-key, and a scene that is closer to 50 % would be considered mid-key.
Low-key lighting will always represent a scene with high contrast, where the difference between the darker and the brighter relevant parts of your scene are more than one stop. The most important aspect here is the skin tones in the darker and brighter sides of the face. Although it can also refer to the contrast between the brighter parts of the skin tones, and the darker parts of the scene. For example, like you can see in Guillermo Del Toro’s Pan’s Labyrinth, or in Tim Burtons, Edward Scissorhands:
To better understand what low-key lighting is, lets think about a high-key lighting situation where there is very little variation between the brighter and the darker parts of a scene, the shadows don’t hide anything, you can actually see all the details, the darker parts of the faces are simply defining shapes but the brighter and the darker elements of the scene occupy very close places in the exposure spectrum.
High-key lighting is very forgiving because everything is well-lit, everything is exposed correctly, and for that reason, it is used a lot in TV shows where the amount of content produced requires a faster workflow that results in a faster turnaround. Imagine for instance, those big soap operas, that put out 365 episodes a year, the need to shoot and edit at a pace that will allow them to deliver a one hour long episode every single day nonstop, that makes necessary a form of lighting where you don’t really have to be readjusting the lighting every other minute.
It is also an option to set a lighter mood to avoid coming across too serious or dramatic.
Low-key lighting in cinema
Low-key lighting will commonly create a much more serious tone. However, we will see exceptions such as in the work of the amazing Gordon Willis on some of the Woody Allen comedies like Annie Hall, Stardust Memories, etc.
If you show too much there is no mystery or fear. That’s why low-key lighting is present in virtually any good horror movie you will ever see. It creates mystery. It will hide nuances in order to leave space for the imagination to run wild with gut-wrenching anticipation.
Both low-key lighting and high-key lighting creates a certain visual language that has influence on the tone, feel and ultimately the way the audience perceives the movie altogether.
Sometimes during a movie, the light can be used the help to tell the story, and even change as the plot progresses.
Chiaroscuro is an Italian term that literally means “Bright and Dark.” It refers to the high contrast utilized in the Renaissance paintings of DaVinci, Vermeer, and especially Giovanni Baglione who used this technique where the subject’s faces are split and exposed one side darker than the other.
That technique would later be utilized by German Expressionist film directors.
German Expressionism directors used exaggerated visuals and fantasy. The use of visual effects, high contrast, low-key lighting, sharp and dynamic shadows, coupled with the surreal imagery that portrayed itself as highly stylized and almost unreal, was a distinct characteristic in those movies.
Another great example of a film style that uses low key lighting is “Film Noir.” Film Noir in French means “Black Film” or “Dark Film.” Even though film noir is used to describe films around the world, most of it is usually associated with American productions as the style derived from the crime fiction that emerged after the great depression.
That style is usually used to tell stories that involve mystery, crime and sexual motivations normally associated with the classic Hollywood crime dramas very commonly characterized using the witty private investigator as the protagonist.
The Classical Film Noir Era goes from 1940-1959, and some of its most famous films are The Big Sleep, directed by Howard Hawks, Gilda, directed by Charles Vidor, and Touch of Evil directed by Orson Welles.
Many of the Film Noir directors were bound by their budget and or their primitive technology which makes it a great starting point for studying lighting.
Among the directors that where influenced by the German Expressionism and masters of the high contrast and Low Key Lighting is once again Del Toro. The Academy Award-Winning director of “Pan’s Labyrinth” and The “Shape of Water” is famous for being able to create convincing parallel universes where the fantastic is normal, where mythical creatures and monsters are present as part of peoples normal lives. He is a big fan of film noir and uses low key light as one of the main elements to convince his audience of the impossible.
Another incredible director extremely influenced by German Expressionism and a master of Low Key Lighting is Tim Burton his surreal and dark looking movies, makes you feel that you have entered a parallel universe meticulously crafted and shaped by Low Key Lighting. Someone could argue that if movies like Edward Scissorhands or Dark Shadows were filmed under High Key Lighting they would never work and would probably look pretty silly. But the dark mode of the lighting made it creepy enough to give the movie a deeper tone that perfectly balances the dark humor.
Of course it would be a sin to talk about Low Key Lighting without mentioning the “prince of darkness” master of contrast, Gordon Willis. He is probably one of the great masters of Low Key and also one of the most influential in film history.
One example of this is found all throughout his masterpiece The Godfather where his revolutionary dark approach became a lesson on how to deal with shadows and the dark elements of a scene in a psychological way. For instance, the mystery of Marlon Brando’s character is revealed in the fact that you can’t see his eyes, and therefore you can’t really read his soul.