Lighting is one of those areas of film or video production that can be thoroughly frustrating if you don’t have the right equipment or a proper understanding of the basics of how to light correctly.
If you wish to light a person in close up and make them look their best you’re best off understanding what is usually termed, “portrait lighting”.
In portrait lighting we use a minimum of three light sources to create an attractive image of the human model. The main tenet here is to attempt to create a three dimensional look.
Yes, I know, most people do have three dimensions to their physical form . . . height (up and down), width (left and right) and depth (further or closer). But remember, the screen we’ll be looking at on playback has only two dimensions - height and width. The third dimension , that exists in reality, must be created artificially for the two dimensional screen using proper lighting.
Imagine a white sphere against a neutral grey background. If we light it evenly from both sides we will likely see what appears (on a two dimensional screen) to be a flat, round disk, like a coin.
If, however we make the left light brighter than the right light there will be a shadow on the right hand side of the sphere that gradually diminishes as it approaches the center. The resultant image on a 2 dimensional screen will appear to be spherical rather than flat. That’s what we want to achieve with our human model.
The usual formula for portrait lighting is that the light on one side should be half the intensity of the light coming from the opposite side. Also, the brighter light, which is called the “key light”, should be a good one third higher up, shining down on the subject, than the less intense “fill light”.
Then there’s a third light called a back light . . . not because it is meant to light the back of the subject. What good would that be from the camera’s point of view? It is meant only to highlight the top of the head and the shoulders. This highlighting will separate the subject from the background to enhance the appearance of depth in the scene. The backlight’s intensity should be the same as the bright “key light” and positioned slightly behind, but high over the subject. The extra height is meant to diminish the possibility of lens flare as it is pointed somewhat in the direction of the camera.
Using this ratio for the key, fill and back lights can help provide a very pleasant portrait appearance.
For wider shots, often encompassing more of the setting and perhaps more subjects, a simple “broadcast lighting” arrangement is often used. This set up involves equally spacing several lights of the same intensity so that the lighting is consistent across the set. While not as pretty as the portrait lighting for close ups, it is much easier to set up and works quite well for wide shots where detail is not so important.
I encourage you to purchase and use a good incident light meter which reads the amount of light coming from individual lighting fixtures. This will help balance intensities for either portrait or broadcast lighting.
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