low key lighting

low key lighting uses a lot of dark tones and shadows. it has a very minimal amount of white and mid-tones and a lot of deep blacks. when taking a photo or shooting a scene with low key lighting, your outcome will have striking contrasts which will help to produce dramatic and mysterious scenes/images that also features a lot of shadows. it was often used in noir films to add contrast to the scene or to emphasise characters and details

to achieve low key lighting, only one source of light is needed. when shooting a photo or a scene, it helps for the background to be deep black or something with a similar kind of darkness than a bright or white one. 

fight club is a good cinematic example that uses low key lighting. in both of the images, there are various shadows and dark tones. low key lighting often only uses one light which tends to be either the fill light or backlight. in the first image, the only light source is the light we see in the background, behind the character. this low key lighting is used to create a dramatic mood. the second image shows predominant shadowy areas, with only one light source coming from above. both of these images from fight club create mysterious and dramatic moods. 

when shooting low key scenes, the background is a lot darker than the face which creates the dark and moody atmosphere. 

this shot from twilight is another cinematic example of low key lighting. the only light source is the fill light which only lights up one side of the characters face. this creates a tense and dramatic mood in the scene. the background is a lot darker than his face. 

references:

https://www.youtube.com/watch?v=qlRKty7uIIg

https://contrastly.com/understanding-the-basics-of-high-key-vs-low-key-lighting/