Three Point Lighting is called three points is that it uses three different lighting sources. These sources are called key light, fill light, and backlight. The key here has nothing to do with opening the door. But the spot where the key light is placed will open other lighting doors as well.
In other words, where other lighting sources are placed will depend on where the switch light is placed. Each of these three sources has different effects on the illuminated scene or object. The three aforementioned lighting sources are directed on the object/scene to be illuminated from different angles, intensities and from different directions. The lights of these sources can be focused or diffused.
By using three lights together, texture, illusion of reality, psychological atmosphere and points of interest are revealed. We talked about three points, but we have four lighting sources. In this case, the answer is simple. If we don't want backlight, three light sources are sufficient;
1. Master Light / Key Light
The key light or main light, referred to as the key light, is our main light and provides the basic illumination of the subject and the scene. In general (if the ambient light is not strong) it is a strong light. Our most important light is the key light, which makes the scene visible and simulates the solar task in nature.
2. Fill Light
Since the key light will be strong compared to the other lights we use, it can create harsh shadows on the objects and living things in our scene. To avoid this, we use fill light. We position the key in the opposite direction of the light. Just as the fill light softens harsh shadows, it is also used for the subject, a place in the scene that we particularly want to appear.
Backlight adds the 3rd dimension to our image and is a very important light. It separates the subject we are shooting from the background. The person we shoot is positioned behind the subject – it is hidden. It creates a line of light around or a certain part of our subject.