Lighting & Cinematography
Using a single key light:
The background and foreground of a shot is lit in a way that imitates the look of it being done with two separate lights, but only one large soft light is used. This technique can be extremely effective if the light and subject are positioned correctly. Usually placed in front and to one side of the subject, the light creates a harsh shadow on the person’s face (due to no fill light) and a very soft shadow on the background as it becomes more defused and further away. Lighting a scene this way is a lot more efficient (if you want this look), because less equipment is used than the usual three point lighting, and therefore cheaper, and quicker to set up once you get the right position.
This is also an example of low key lighting. Only one key light is used to light a scene, to create a lot of darkness from shadows, sometimes the filmmaker chooses to use a reflector or fill light on a very low opacity as well, with the ratio 8:1.
Examples of Lighting Effects/Tempurature/Depth of Focus
An Eye for an Eye (1981)
In the very first clip of the trailer for ‘An Eye for an Eye’ (1981), there is an example of deep focus, allowing Chuck Norris to freely run towards the camera without going out of focus, or the the camera operator having to quickly and precisely change the focus.
Deep focus is achieved with a large depth of field; directors use this to make sure they keep everything that’s in shot, sharp, usually seen in establishing and long shots, or scenes where the subject is changing their distance from the camera, like this one.
The Exorcist (1973)
The director of ‘The Exorcist’, William Friedkin, sought out a different approach to lighting his movie compared to the usual spooky lighting of horrors. Throughout the film, each scene was made to look like the light was coming from a source within their world; like the lamp being turned on to the right of the girl in this one, just off screen. This is an example of practical lighting, by having it come from the scene.
Friedkin wanted to make sure it was realistic and so his cinematographer, Owen Roizman, always kept the practical light the key light. However, a blue filter was added to them to hold onto the eerie atmosphere and match the coldness of the room (which they kept air conditioning on all night for, creating below-freezing temperatures).